do you know is it possible to change or add geo-tag localization in Exif data of .JPG photos? Is there any plugin for that? I cannot find any clear answer is it possible from the graphical application on Windows?
In Gimp 2.10, the dialog that you reach via
Image>Metadata>Edit metadata has a "GPS" tab.
This is a new feature in Gimp 2.10, IIRC.
Edit: it seems to be too buggy to be usable. The longitude and latitude values are truncated if you edit them...