Are you looking for an agent for public relations? If you know please tell me.
Are you the owner who find a promotional services or you are the agent? since your post is little bit confusing but if you are the owner well I will give you the options where you can promote your sportsbook.
1. get a campaign manager(I suggest him
https://bitcointalk.org/index.php?action=profile;u=355846) who will manage your signature campaign and social media campaigns.
2. Find Locals who will promote your service on their respective local languages.
3. Hire youtubers to create a video reviews for your sportsbook.