Add Existing or Invite New User
- Click Settings

- Go to Permissions for that site

- Click Add user

- Add the user
- If user exists: Select Existing User.
- If new user: Click Add User to invite them.

- Uncheck "Add to group" (unless you want group permissions).

Set Permission Level > Add Module (Required)

Assign Content Permissions
- Navigate to content
- Click Content.
- Select the manual, chapter, or article.

- Add User
- Click Custom.
- Click Add User.

- Select User > Permission Level > Add User
- Select the user
- Permission level: Review, Contribute, or Manage
