Foreign work experience for canadian express entry HELP!!

I am a dentist with 3yrs of experience working at my own clinic legally owned by my parents (who are also dentists). Unfortunately, i don't have a steady salary per se but i receive some payments via the patients directly or by my parents at month end (which even extends to next month sometimes) in the form of cash or UPI or both. I do transfer the money in my bank account regularly. There is no steady "proof" of my salary which i think will make the officials raise questions. In situations like these where the person is self employed, what do you think would be the best thing to do?