Question encrypting files to flash

[TAWM]

Samsung Galaxy s21+
Recently purchased a dual flash drive so I can plug it directly into phone and free up space on the phone. I am wanting to password protect these files on the drive so others cannot see them. I was able to use Rohos on my desktop to create the hidden/locked file on the flash drive but now my phone will not recognize the flash drive. Making it useless.
Anybody know how I need to proceed?
At some point I will need to take the encrypted files out of the encrypted folder to share. Please help and thank you.

 

[AdrianBaw]

It looks like the encryption method you used with Rohos may not be fully compatible with your phone. You might want to consider trying a different encryption tool that supports both desktop and Android, such as EaseUS or AxCrypt.

 

[TAWM]

It looks like the encryption method you used with Rohos may not be fully compatible with your phone. You might want to consider trying a different encryption tool that supports both desktop and Android, such as EaseUS or AxCrypt.

Thank you so much. I will google those and see if they will work.