This article shows you, the admin, how to check-out people using the self-check-in link.
Click on a list, you will be redirected to the list browser page (how to create a list).
Hit “List Options” → “List Details” or go to “Lists” → three dots under options → edit
Change “Allow Check-Out” to “Yes” and save the changes
The changes to the self-check-in link will take place immediately, and people will see the check-out option when they put in their name
From the list browser page, tap the information icon → “List Details”
Under the profile, toggle the switch titled "Allow Check-out"
Dashboard Screenshots (Admin):
iOS Screenshots (Admin):