Completion requirements
The invocator is not an official Toastmaster role, but it is common enough that it merits a guide for doing it well.
2. Performing Your Role
2.2. During the Meeting
If your club has an invocator role, usually the presiding officer will call on you to come to the front of the room near the beginning of the meeting. Transfer control, pause briefly to let applause settle, then deliver your invocation. When you are finished, transfer control back to the presiding officer and take your seat.
If the presiding officer forgets to call on you, raise your hand and state "Point of order: We need to have the invocation."