Step 1: After receiving invoice in the inbox, clients see the button for "Paypal" and "Stripe" in the invoice itself.
Step 2: Clients clicks on the "PayPal" or "Stripe" button to choose their payment method.
Step 3: After clicking on the PayPal button, the client gets redirected to the PayPal login page.
Step 4: The client logs into their PayPal or stripe account using their registered email address and password and pays for the invoice.
In the similar manner clients can pay using stripe as well.