SANDISK USB-C problems

Which exact model is your SanDisk drive. Typically, they come formatted as FAT32 when they are < 32 GB, & exFAT when > 32 GB in size. Either format should be readable by your Mac.

Do you have external drives showing in the Finder app? If you open a new Finder window, your SanDisk should appear under the Locations category on the left-hand side of the Finder window.

To have it appear on the macOS Desktop, with a Finder window open, and from the macOS menu bar, select Finder > Settings > General. Be sure that External disks is selected.

Also when connecting an external drive be sure that in Finder settings you have permitted external drives to show.

Jasperoscarmax wrote:

... the setting are set for external drivers, the drivers are for an android.

Not exactly sure what "the drivers are for an android" means. What drivers are you referring to? Neither your Mac or iPad would require any drivers to access an external USB drive as they are "seen" by both Macs as a USB device.

Just about any brand USB flash drive, HDD, or SSD, should work with your Mac. However, not all do work with the iPads.

How is it formatted?