How does a team protest a decision?

Under Rule 23.2.4 and 27.2.3:

1. The 1st referee does not allow any discussion of decisions. However, at the game captain's request, the 1st referee must explain the application or interpretation of the rules on which the decision was based. Only the game captain may ask for clarification.
2. If the game captain disagrees with the explanation and wants to protest, they must immediately reserve the right to file and record the protest at the end of the match. The 1st referee must authorise this.
3. At the end of the match, with the 1st referee's authorisation, the scorer writes (or lets the team or game captain write) a statement on the incident on the score sheet.
4. The scorer signs the score sheet first, then gets the team captains' signatures, then the referees'.

During the match, the 1st referee's decisions are final.