Why not use the storage access framework, which is agnostic to where the files are being saved whether local or remote? By selecting the file to open or naming it to save, you choose a destination and permission is implicitly granted to that location for that file. Could be google drive or the local file system or any cloud provider app that supports SAF. No storage permissions needed, and it's been around for years and years.
https://x.com/Tesla/status/1954992987223757149