Open as root for editing a /usr/share/polkit-1/actions/org.freedesktop.UDisks2.policy file:
sudo nano /usr/share/polkit-1/actions/org.freedesktop.UDisks2.policy
Here we find the rule beginning with the following:
<action id="org.freedesktop.udisks2.filesystem-mount">
And at the bottom of this block, modify the following sections about this:
<defaults>
<allow_any>auth_admin</allow_any>
<allow_inactive>auth_admin</allow_inactive>
<allow_active>yes</allow_active>
</defaults>
to:
<defaults>
<allow_any>yes</allow_any>
<allow_inactive>yes</allow_inactive>
<allow_active>yes</allow_active>
</defaults>
Then save the file.
https://en.linuxportal.info/tutorials/troubleshooting/how-to-clear-the-not-authorized-to-perform-operation-error-message-when-automatically-attaching-USB-flash-drives-and-other-external-USB-storage-devices