You must have Team Page "Full Access" or "Limited Access - HQ Tools" permission to send RSVPs reminders.
NOTE: First, you must create an event or game to send RSVP to your players or staff.
If you didn't send out RSVP Invites when you created the event or just want to nudge someone who hasn't RSVP'd yet, you can send them a "reminder." This is just a brief message to remind them when the event is and ask them to RSVP if they haven't yet.
Send Reminder
Sign in and go to your team's TeamCenter.
On the left-hand navigation, click on the Schedule tab.
Click on the event or game "name" from which you want to send reminders.
Under the "name" of the game or event, choose either the Player RSVPs or Staff RSVPs sub-tab.
Check the box next to the player or staff to which you want to send a reminder, then click the blue Send Reminders button.
Click Send to confirm.