I am unable to read a san disk flash drive on MacBook pro 2023

Connect the USB stick directly to the laptop. If you need to use a USB-C to USB-A adapter, then try using another one in case it is bad or incompatible.

Disconnect all other external devices in case one of them is causing a problem.

Boot into Safe Mode to see if you can use the SanDisk USB stick. If this works, then you most likely have some third party software installed which is interfering with the normal operation of macOS.

While the SanDisk USB sticks seem to be more reliable than most others, I do agree with @ku4hx that many USB sticks are unreliable and you can still get defective ones even when a manufacturer generally produces a good product.

Is this an older or newer USB stick? Not all external devices are compatible with an Apple Silicon Mac (usually older devices though). Are you able to try the USB stick with another computer (especially another older Mac)?

Does Disk Utility even see the physical USB stick? Within Disk Utility you may need to click "View" and select "Show All Devices" before the physical drive appears on the left pane of Disk Utility.

There's nothing special about a flash drive. They're unreliable in my opinion but that's just me.

What format is it? Attach the drive, open Disk Utility and make sure the drive is formatted in a Mac format. Many drives come formatted for Windows.

Theoretically, exFAT should work for both Mac and Windows, but my experience is that is not 100% true.