I suggest not focusing too much on finding a freelancing activity that pays in Bitcoin.

Try to focus on those fiat payments then have some of your earnings to be allocated in buying Bitcoin.

Your first option is to find freelance works established in your country. That way, you might be convenient in the application. There are BPOs who are also looking for freelance workers so try looking at it.

You can also consider looking here: https://www.hostinger.ph/tutorials/best-freelance-websites