These are instructions to link cash app, then begin converting some percentage of your total sales (credit cards) into bitcoin via cash app.

This unfortunately does not allow accepting bitcoin in square. Depending on the use case though, having cash app already enables people to accept bitcoin since they have access to an address there.

If they want to exchange goods for that bitcoin, it’s up to them. Kind of like a cash transaction that doesn’t make it into your POS ¯\_(ツ)_/¯