Sharing a record with read-only access is a feature that is available on the Pro and Enterprise plans.
Free and Plus plans have access to the standard item share tool, which gives guests full read and write access on a shared record.
To share an item, first click the “Share” button in the upper right off the record window.
From here you can select the person you’d like to share the record with, using their email address then enter a brief message to let them know what you’re sharing.
Check the box at the bottom left of this window to enable read-only sharing.
This lets the guest view everything within the record, without giving them access to modify any of the fields there.