OSX photos can’t import

Photos library should be on APFS or MacOS Extended -formatted volume.

Other formats like exFAT, NTFS etc are not supported, and if they initially seem to work, they might corrupt the library later.

Are you trying to import photos from a Photos Library on your external drive or to import photos into a photos Library on your external drive?

Your question is not quite clear, sorry, because Photos can now import photos directly from another Photos Libraries - this is possible since macOS Monterey.

I second Matti Haveri's recommendation to check the file system format of the external drive. The external drive needs to have a compatible file system format and it needs a wired connection, you must not keep the library on a file server accessed over the local network.

The requirements for an external drive are described here: Move your Photos library to save space on your Mac - Apple Support

Make sure that your external storage device, such as a USB drive or Thunderbolt drive, is formatted for Mac: either APFS format or Mac OS Extended (Journaled) format.

You can't store your library on a storage device used for Time Machine backups. And to avoid possible data loss, don't store your library on a removable storage device like an SD card or USB flash drive, or on a device shared over your network or the internet, including over a cloud-based storage service.