https://www.speechanddebate.org/rules-forms-manuals/
The NSDA's Unified Manual dictates the rules and procedures for the National Tournament.
In relevant part:
"Supervision: In order to compete in the National Tournament, each student must be supervised by an adult approved by the principal. The adult supervisor must be the student’s coach, a school district faculty member or administrator, or the child’s own parent(s). The supervising adult must stay at the same lodging with student(s)
under their supervision. Students without an accredited supervisor staying in the same lodging will not be permitted to participate in the tournament. Coaches from other school districts may not be the adult supervisor without prior written permission of both school district superintendents submitted to the Association before the entry will be accepted."
There are also a number of required forms submitted by entrants to the National tournament, including a signed "Rules" form - those are made available each year directly to qualifying entrants.