You want to use the Online Registration and also allow online payments;
Go to Menu > Manage > Tournament Registration > Manager User Registration.
Click on Event Settings,
*Turn on User Registration by clicking on Accept User Registration.
Check the Accept Online Payments checkbox.
The Stripe and Square connection button will be there.
Follow the steps to create your account!!!
Also:
Make sure your divisions are registerable (Menu > Manage > Divisions > Divisions.)
Select division,
Pencil to edit.
Go to Pre Registration section.
Enter information.
Save.
If you don't have divisions already created, you can create them under Divisions or Directly under Manager User Registration.