Karma is a word derived from Hinduism and Buddhism. It simply means your actions will influence your experience in life. It’s otherwise known as “what goes around comes around”.
Whilst the bible never expressly uses the word “Karma”, there is a similar concept of the idea of “what goes around comes around”. The bible commonly talks about reaping what you sow.
Job 4:8: As I have observed, those who plow evil and those who sow trouble reap it.
Galatians 6:7: Do not be deceived: God is not to be mocked. Whatever a man sows, he will reap in return.
Ephesians 6:8: Remember that the Lord will reward each one of us for the good we do, whether we are slaves or free.
The main difference between this Hindu/Buddhist concept and what the bible says is that karma is a cosmic response whilst the biblical concept is God actually rewarding each individual for their actions, whether good or bad. It is rooted in the justice of God. A clear demonstration of this is God repaying David for what he did to Uriah (2 Samuel 12:11).
Colossians 3:25: But if you do what is wrong, you will be paid back for the wrong you have done. For God has no favorites.