post https://api.safetyculture.io/groups//users/v2
The Add User to Group endpoint allows any user with Group Management permissions to add a user to a group within their organization.
A user can only be added to a group within the requesting user's organization and only users within the requesting user's organization can be added to a group.
When a user is added to a group, the user inherits the permissions of the group they are added to.
The endpoint returns a list of all users in the group after the add user operation is complete.