You may need to click > next to This PC first in order to view the flash drive.
For example, you might need to confirm that you want to repair the drive by clicking Scan & Repair.
If the flash drive’s internal storage is damaged, your only viable option is to take the drive into a professional repair service. The prices for data recovery can vary from $20 - $850 based on the severity of damage to the drive, and the type of recovery required.