How to laravel eloquent belongToMany relationship with internal class constant?

Question

I have

• table groups
• table group_has_permissions (as pivot table)

I dont want to create permissions table because I knew there would be like 3 fixed permission . I think its kinda overkill to create a table for 3 rows only.

So I went on a search for alternative

• Where to put/how to handle enums in Laravel?
• https://medium.com/@kiasaty/how-to-avoid-enum-data-type-in-laravel-eloquent-1c37ec908773

But when I got into articles, I found that the enums/class constant are stored within the same model/table and do not work with eloquent relations. What I do want is instead of creating a table/model for the permissions table I would like to refer it in a more simple config array or enums/class constants.