Looks like boxing is open entry, as per QS
In view of the fact that the event will be a qualifying for the Paris 2024 Olympic Games, all the National Olympic Committees may participate in the Pan American Games and register additional athletes in the categories that they have not qualified for yet, considering the following:
• Only one athlete per NOC may participate per weight category.
• The athletes must be registered and accredited by their NOC through the Santiago 2023 system and within the dates established for the Pan American Games. • Additional athletes will be accommodated in accordance with the provisions of the boxing policy that can be found on the extranet and in the Chef of Mission Guide.
• All the expenses must be covered by the NOC or by the National Federation (airline ticket, accommodation, transportation, meals).
• The additional athletes will receive an accreditation for the Pan American Games and if they win a medal, they will be eligible to receive it.