I thought you said you were doing sigil work, not invoking? These are two different things.
If you’re doing an invocation don’t even bother with the board, the spirit will be literally inside you and you can sense it as if you were talking to yourself.
If you’re doing sigil magick, then open the sigil first.
Then when the sigil is open, at this point say thank you, and state aloud that you are asking the entity to speak to you though the ouija board.
State no other entities are allowed to talk though the board, just Amaymon.
Then place your hands on the planchette and let it flow. Start by asking if it is Amaymon and to flash you his sigil to your mind’s eye.
Proceed with othr questions as you see fit.
At the end, say thank you and that you are leaving, and if you like say “please feel free to depart” or “I give you license to depart”.
Traditionally, push the planchette to Goodbye, before removing your hands.