Allow editing a certain field for users who has only read access

Hello community. Just came across a small mishap on my end.

We’re handling about 80k documents in a certain doctype, and 20 users with different roles have the permissions for READ. We would like those users to WRITE to only one field.

How can we achieve this?

Thanks guys.

Use permission level to allow write access to that 1 field.
https://docs.erpnext.com/docs/v13/user/manual/en/setting-up/articles/managing-perm-level