While creating your event (league), you are asked if you want to use the League Fee Payment feature. If you said no at the time but changed your mind, you can turn it on by going to:

Menu > Manage > Event > Event

Select your current league;

Pencil to edit;

Click on the Weekly Fees/League Fees Payments section;

Accept League Fees (Weekly Fees) Payments? Check the box.

When you check the box, the system will ask you if you accept the charges that come with using this feature.

If you agree, say yes.

And Save.

What is the cost to use the League Fee Feature (Weekly fees/Online Payments)