1/ You've sent a request to the guest to ask for an (advance) payment. (check the tutorial here)
This booking is now 'pending' as you are waiting for the guest to pay for his stay.
2/ The guest receives a payment link
TIP: Check here how to personalize e-mail templates
3/ The guest will be redirected to the following page
4/ The guest can pay for his stay by credit card (or by another payment method if activated)
5/ Once the guest has paid this will be registered automatically in ManCloud
6/ This booking is now completed