Won't install in Pop!_OS

[DieGT]

`Installing theme in /home/diegt/.mozilla/firefox/weeufqvs.default
Coping repo in /home/diegt/.mozilla/firefox/weeufqvs.default/chrome
cp: no se puede crear el fichero regular '/home/diegt/.mozilla/firefox/weeufqvs.default/chrome/firefox-sweet-theme/.git/objects/pack/pack-17f4d0f93b9d8c08fdaffadaa1a413898f08056d.pack': Permiso denegado
cp: no se puede crear el fichero regular '/home/diegt/.mozilla/firefox/weeufqvs.default/chrome/firefox-sweet-theme/.git/objects/pack/pack-17f4d0f93b9d8c08fdaffadaa1a413898f08056d.idx': Permiso denegado
Set configuration user.js file
ln: fallo al crear el enlace simbólico '../user.js': El archivo ya existe
Done.

Used the automatic/fast instalation script, tried it before, the install.sh script won't run...? next to it, there's now a chrome folder and a user.js file