Unable to rewrite spreadsheet content

I wanted to rewrite the contents of the spreadsheet, so I clicked [Script Editor] to rewrite the contents, selected [change Color] and clicked [▶], and the message "Approval is required" came out, so I clicked [Confirm Permission] and the following message was displayed.

It is true that the account of the person who wrote the script on this sheet was deleted about a month ago, but is it possible to rewrite the contents of this sheet?
I looked it up online, but I didn't understand it well.(In the first place, I don't understand the concept of OAuth itself.)
When I deleted the account, I transferred the owner's rights, but I didn't know about OAuth.
Please let me know if there is a good way.
I am quite unfamiliar with these things, so I would appreciate it if you could explain them in as simple a language as possible.