Some gyms will charge a yearly maintenance fee or something similar to all active members.
Here is how to set that up.
Create a new Plan
Set recurring amount to fee amount
Set recurring interval to 1 year(s)
Set 'Allow Check-Ins?' to NO, because this is not a plan you want showing up on the check-in app for an option to people to check in to.
Toggle 'Show Waiver' to NO, likely not necessary for this.
You should add this plan to them manually when join. It will charge them the amount now, and then each year on that same date. If you want to charge everyone on the same date each year like Jan 1st, then when you add it, select that date as the 'next bill date'.