Read only_Edit Icecat.desktop

[segundomail]

Hello, 
I recently ran into a small problem that I would like some help if possible. I 
use Guix Package Manager on ubuntu and I have a small problem with the icon of 
the browsers, all the ones browser installed are redirected when opened to the 
icon of the icecat (palemoon, librewolf etc) in the dock (native in gnome and 
plank on kde). I checked and I believe the problem is in the icecat.desktop 
where the tag is StartupWMMClass=Navigator, and speculate that it should be 
StartupWMClass=icecat-default, I may be wrong, but before guix it didn't happen 
(I edited the others' StartupWMMClass to make sure). however I can't edit the 
icecat.desktop because it is read only, is there any way to edit the .desktop 
to check if this is what creates the problem or solution?
 Thanks for your attention;

Dionatan Felipe De Souza