Adding Payment Options to Booking Form

I have this Booking Form Lightbox (see image attached) that was created with this tutorial https://support.wix.com/en/article/corvid-tutorial-creating-a-bookings-timetable and I have Paid Plans App active on my site.
I want to add to the booking form an option to choose the payment method (either one time direct payment OR choose paid plan) - The same one that comes in the default booking form (see image attached), together with the option to log in.

How do I do that?