In Mozilla Thunderbird it’s pretty simple – saved passwords from email accounts are stored in the settings.
To open them, open the “Settings” by clicking on the icon on the right in the top corner in the form of three horizontal lines, then select “Settings” and in the submenu again “Settings.”
In the window that appears, select “Protection” and go to the “Passwords” tab.
Next, click on the “Saved passwords“.
In the next window that appears, there will be a list of accounts for which passwords were saved, at the bottom click “Display passwords” and another column with passwords will appear in the list.