Open an item you own, open its menu and choose Lend it out. Enter Who has it, check the lending date and optionally set Back by. Confirm the loan. Lending does not archive the item or transfer ownership.
With a return date, you can enable Remind me to ask for it back and allow notifications. If permission is denied, the loan is saved without the reminder. This reminds you on your device; it does not message the borrower. Open Out in the world in Workbench to find lent items. When one is returned, open it and choose It’s back. This clears the loan and cancels its reminder.