UEFA tells Euro 2024 teams that only captains will be able to approach the referee in matches - and any other places "who approaches the referee showing any sign of disrespect or dissent will be booked.
If captain is a goalkeeper, a teammate can be nominated to approach refs.
UEFA MD of refereeing Roberto Rosetti: "We want only the captain from the team who wishes to discuss a decision to be able to approach the referee. It is the responsibility of the captain to ensure his teammates respect the referee, keep their distance and do not surround him"