Editing Host URL Information WITHOUT Admin UI Access?

I’ve been painted into a wacky corner here, and I’m hoping someone can help me figure a way out. ??

Somewhat briefly: running a WP site on our corporate network. IT had set up a URL for me when we originally set up the site: https://foo/ and then later, also https://foo.corp.mycompany.com/. All the host URL entries entered during WP setup were entered as https://foo/, and all was working well for a while.

We’re now finding that https://foo/ isn’t properly resolving, so I no longer have access to https://foo/wp-admin/index.php to get in and fix the URLs. But I *do* have FTP access (or direct SMB access in some cases, too).

So the question is: can I fix this by directly altering files versus the UI? And if so, what files should I access (via TextEdit, etc.) to alter these host URLs to fix this stupid problem?

Thanks!