A match official can not be sent off and don't have to leave. They are required to referee the game or help the referee. A "team official" however has to do all those things if sent offThe match official is required to leave the technical area and the vicinity of the field of play such that they cannot practically be further involved in the game. If they refuse to depart the vicinity of the FOP you should not restart the game.
And in youth football and mini soccer if the club official is the only responsible adult (inclduing DBS-checked, etc.) with their team, tell them they have been sent off but may remain in the vicinity for Child Protection purposes only - if they don't behave after that, abandon, get paid, go home, report.Consider if they are also classed as physio, things might work slightly differently...
They can potentially stay but any more issues from them and game is at risk of being abandoned.
Competition rules rather than LOTG.On this subject, one that I should probably know, but I must hold my hands up and say I don't / didn't.
I found out in the summer that apparently a manager (or other team official) who has been sent off must go somewhere that doesn't afford them a view of the FOP. (i.e. they can't sit in the stands)
I'm quite sure I recall Arsene Wenger being sent off in a Man Utd v Arsenal game years ago and him going in to the stands where he got loads of stick from Man Utd fans... so either I've totally imagined this or that rule has changed?