I took a time to find this verse
“And when they had made selection of some to be rulers in every church, and had given themselves to prayer and kept themselves from food, they put them into the care of the Lord in whom they had faith.”
— Acts 14:23 (BBE)
“And from Miletus he sent to Ephesus for the rulers of the church.”
— Acts 20:17 (BBE)
There are more than it but I can't specify it
I hope you understand that Paul and the others were choosing leaders in the early churches and not Apostles. Here is an article that explains the pattern of leadership as presented in the early church,
Introduction
After Jesus Christ’s ascension, earthly authority over his church fell first and foremost to the eleven remaining of his closest disciples, Matthias – the replacement chosen for Judas of Iscariot – and James the brother of Jesus who was appointed head of the church at Jerusalem1. Paul, after his dramatic conversion, quickly became a leader of the church as well, and was confirmed by James, Peter, and John as an apostle to the gentiles2. But as the church grew, and news of Christ’s death and resurrection spread far and wide, it was clear that leaders would have to be appointed among the churches of every city to teach, admonish, and care for the needs of those growing congregations. To this aim, the apostles (and doubtless others as well) appointed leaders in the churches, and further delegated the task of appointing such men to others whose faith and character they deemed to be worthy of such trust3. So, by at least the middle of the first century, the basics functions of an episcopal leadership had been established.
Although there were many varied functions carried out by a number of members in the early church*,
the basic leadership structure seems to have fallen into three categories: apostles, elders, and deacons.
Apostles
The term “Apostle” (apostolos) literally denotes a messenger or one who is sent by another, but in the early church it took on a new significance – that of one who was sent by Jesus Christ. This term was used to varying levels of exclusivity, at times only denoting the original eleven disciples and Matthias, while others, such as Paul, use the term more broadly to include other preeminent leaders in the church such as James the brother of Jesus4 and himself. As Paul frequently referred to himself as “Apostle” in his writings, there can be little doubt that he was generally included in this elite group.
The Apostles were the preeminent authorities of the early church after Christ. It was the apostles who appointed the first elders, instructed them in doctrine and conduct, and whose writings were paired with scripture5. Even after the Apostles had departed a region – indeed even after the last of the apostles had passed away –
the station of apostle remained unique to them, as did the authority of their teachings.
Elders
Several terms were used to denote those men appointed as leaders over the local churches. Although here they will be referred to simply as “Elders,” they were
alternately called “overseer” (episkopos)
, “shepherd” (Poimen), and
Elder (presbuteros)+. These terms were used synonymously without any distinction drawn between them. The term “presbuteros” can also be translated simply as “
presbyter,” and Poimen (shepherd) has also come to us as “
pastor” (from the Latin, Pastorem). Episkopos, through a later etymology, is also rendered “
bishop.”
As mentioned before, the Elders were appointed to provide leadership and guidance to the local churches in the absence of the Apostles. As the number of Apostles dwindled and those who remained knew their time was short, they entrusted care of the churches fully in the hands of these Elders, admonishing them to remember the doctrine they had been taught and to hold fast to it in the face of new trials and innovative heresies6.
The duties of elders were undoubtedly many and varied, but the most important of these duties were the instruction of sound doctrine7, exercising oversight over and setting an example to the congregation8, acting as a bulwark against false teachings and dissention9, and praying over those in need among the believers in their charge10.
Deacons
Directly subordinate to the Elders was the “deacon.” (diakonos; a servant who carries out the command of another). The deacons were tasked with assisting the Elders in their duties, which allowed them to provide better care for the flock while focusing on the most important duties of an Elder^.
Qualifications For Elders and Deacons
The position of Elder and deacon alike was a position of great responsibility. As such, much was required of a candidate for these posts.
A candidate for Elder or deacon was to be “above reproach,” a faithful believer for some time, and with a wife and children of similarly high regard. New converts were not eligible for either of these roles11.
Only men could serve as Elders of a church12. It is possible, though not certain, that some women may have served as deaconesses in the church, though the exact nature of this role is not clear13.
The Evolving Episcopate
It is interesting to note that the first elders almost certainly did not hold sole authority over a local church. Rather, it seems the local churches were instead each governed by a college of elders. This can be seen in the Acts of the Apostles, where a council of elders is described in Ephesus and a number of elders was found along with the apostles in Jerusalem14. Similarly, in his letter to the Philippians, Paul refers to multiple overseers at that church15.
Indeed, there is no example in the New Testament writings were any church is explicitly said to have only one Elder, rather all seem to have had a plurality.
From the writings of early second century elders such as Ignatius of Antioch and Polycarp,
this situation seems to have changed drastically from the mid-late first century. Of Ignatius’ 7 letters, only one seems to indicate a city still ruled by a number of Elders**, and Polycarp is said to have been appointed as Elder over the church at Smyrna by John himself at the end of the first century16.
Although this evolution should not be viewed as intrinsically negative, it did set the stage for the onset of an Imperial Church in the fourth century, where the humble servitude of the first elders was swallowed by the pomp and glory of a royal court in which richly adorned "bishops" vied for ever growing prestige.
Footnotes
* See 1 Corinthians 12
+ For example, episkopos is used in Titus 1:7, presbuteros in 1 Peter 5:1, and poimen in Ephesians 4:11
^ cf. Acts 6:2-4
** Ignatius’ Epistle to the Romans
1. Eusebius, Ecclesiastical History, Book 2, chapter 1
2. Galatians 2:9
3. Acts 14:23, Titus 1:5
4. Galatians 1:19
5. 2 Peter 3:16
6. Acts 20:17-38
7. Titus 1:9
8. 1 Peter 5:1-4
9. Acts 20, Titus 1
10. James 5:14
11. 1 Timothy 3
12. 1 Timothy 2:12
13. Romans 16:1
14. Acts 15, 20
15. Philippians 1:1
16. Irenaeus, “Agaisnt Heresies” Book III, (cited from Eusebius, Williamson translation, p. 167)