In ClickUp, guests are added to Folders, Lists, and tasks. To add a guest, find what you want to share, and invite your guest to it!
How to add guests to Folders, Lists, and Tasks
Click the action menu ... (shown below)
Open the Sharing menu
Type the email address of a guest you'd like to invite
Set their permissions
Folder Share Menu
List Share Menu
Task Share Menu
Guest access can be managed from the same
... menu that is used to share the task, List, or Folder.
Click on your profile avatar in the lower left corner of your screen
Gueststo open the Guest tab