NEXUS- https://tpp.nexustours.com/login/?returnURL=%2Fdefault.aspx I will create you an account for this.
ISLAND ROUTES- https://www.islandroutes.com I USUALLY CALL ISLAND ROUTES 1-877-978-1915. Island Routes is the excursion company that partners with Sandals and Beaches. Every Sandals and Beaches resort has an Island Routes desk in the lobby.
VIATOR- https://travelagents.viator.com Click log in and sign up. You can send a link to a tour straight to your clients, they can book it and you get the commission. You will see a link at the top called share with your clients. Super simple.