What is karma? What is akarma?
The kartabhav that I am doing everything - is the cause of all karma. Akarma is when everything is happening externally, but one does not have the feeling of kartabhav (doership).
Only when we have that vision of akartabhav, can we get rid of karmas. And such vision comes with Gnan / Self-realization. The Gnan that Arjun had when fighting his war in Mahabharat, that actions are subject to scientific circumstantial evidences.
To learn more, visit:

In English: https://www.dadabhagwan.org/path-to-happiness/spiritual-science/the-science-of-karma/

In Hindi: https://hindi.dadabhagwan.org/path-to-happiness/spiritual-science/the-science-of-karma/

In Gujarati: https://www.dadabhagwan.in/path-to-happiness/spiritual-science/the-science-of-karma/