Nick here from Shopify.
There are a few requirements to integrate Shopify Payments to your store and having a bank account is one of them. I will list some of them below:
Make sure that your bank account meets the following requirements before you connect it to Shopify Payments:
You can see the guide Shopify has for this going into more detail about it all here.
You could accept money into the account you connect your store to and then transfer it to PayPal should you wish, but you wouldn't be able to put it directly into PayPal unless the customer decides to pay via that method. Let me know if you have any other questions!