You shan't even light it.
Ye shall kindle no fire throughout your habitations upon the sabbath day. (Exo 35:3 KJV)
Do you seriously think not lighting a fire, by which means you keep the law, will get you into heaven?
The scripture you quote is in relation to
doing work under the civil laws of Israel in the OLD Covenant. You do not have to worry about kindling (preparing) a fire if you have done your preparation before the Sabbath starts on the preparation day (thurday evening to friday evening).
Exodus 35
1, And Moses gathered all the congregation of the children of Israel together, and said unto them, These are the words which the LORD has commanded, that you should do them.
2, Six days shall work be done, but on the seventh day it shall be to you a holy day, a sabbath of rest to the LORD: whosoever does work on it shall be put to death.
3, You shall kindle no fire throughout your houses upon the sabbath day.
At the time this was given most work was conducted using fire were work was required to make fire (collecting wood, kindling making fire). This is why there is a preparation day before the Sabbath starts.
We are not living under the OLD Covenant laws of Israel we are in the NEW Covenant now and it is lawful to do good on the Sabbath. All preparations must be done before the Sabbath starts.