Using Debian, I "wrote/burned" an ISO to my newly bought Sandisk USB flash drive. It was a success.
The command I used was
sudo dd if=<file> of=<device> bs=4M status=progress; sync
I need to replace a folder on the USB thumb drive with a folder that has the updated information.
Unfortunately Debian tells me the flash drive is read-only.
I have searched the internet for answers and none of them worked.
For your information, I followed one of the suggested methods and modified the contents of the file called fstab by adding to it the UUID of the plugged-in flash drive.
When I rebooted my device, I was immediately locked out of my root account.
I appreciate your help in this matter.