Is your account set to either “creator” or “owner”?
If so, and you still can’t edit that field, I would reach out to firstname.lastname@example.org to ask them about this. Be sure to post back here with what they say!
He answered me this:
Alex from Airtable Support here ?? Happy to help!
It seems you are aiming to use a formula field as the primary field. The primary field (the first column in any table) can be configured as a formula, which takes data from other fields in the table to compose a unique name for each record. This can be useful if your table does not lend itself particularly well to a single unique primary field.
For more details, please feel free to check this article.
It’s certainly not a solution…I just can’t write inside the formula field…