[@HarFanG]
@ HarFanG
I had a version of Firefox (version 115) downloaded from PortableApps. In its contents there is an “App” folder, which contains a “Firefox” folder and another “Firefox64”.
I was looking for Thunderbird passwords (which in parentheses is not mentioned when clicking on the “i” icon next to Email on the program’s home page).
Following your post, I clicked on Email, then on “Custom Password Recovery” in red. In the window that opened, I was able to choose the “Thunderbird” client.
The path where the Thunderbird profile is usually located is automatically filled in the first field, but for it to work I had to add the profile name there myself!
Below this field, there is the field to mention the location where the famous file “nss3.dll” in 32-bit version is located. I simply indicated the path to the “Firefox” folder mentioned above.
I guess if you follow the same procedure you should access Firefox x64 passwords.