This will most likely require a review by an admin. Only users with a profile may suggest new genres
Workflow might look something like:
User cannot find a genre they searched for, so an option appears that lets them submit it for review. Probably will need to be a separate page, or present user with a button that reveals a new form? Idk
The users submits the genre for review
Either in the admin center or on a restricted page on the website that only site admins may access, or maybe even a completely separate tool/application to handle these sort of queue-based requests, the list of suggested genres appear.
In that list of user-suggested genres, admins will have the ability to modify and approve (or just approve) or decline a suggested genre.
Once approved, the genre gets added to the json file that contains all of the genres.
This will most likely require a review by an admin. Only users with a profile may suggest new genres
Workflow might look something like: