Are you sure PayPal supports BTC and other crypto? Because I can't find a crypto option or wallet on my PayPal account, it only supports local currency.
Or is PayPal BTC not supported in my country yet?

Anyway, I think it's not a good idea to use PayPal to buy something online and settle it with BTC using PayPal.
You don't have full control of your wallet; it's still good if you have a non-custodial wallet.