How do I add start parameter to a program installed via snap

I'm using Ubuntu 18.04 and want to add a few starting parameters to a program installed as a snap package.

The programm (Gitter) is in my dash and i want it to start with the parameter --force-device-scale-factor=2

Thanks

Solution 1:

Found the solution.

Go to folder /var/lib/snapd/desktop/applications and right click "gitter-desktop_gitter-desktop.desktop" and open properties.

The command must change from this

env BAMF_DESKTOP_FILE_HINT=/var/lib/snapd/desktop/applications/gitter-desktop_gitter-desktop.desktop /snap/bin/gitter-desktop %U

to this

env BAMF_DESKTOP_FILE_HINT=/var/lib/snapd/desktop/applications/gitter-desktop_gitter-desktop.desktop /snap/bin/gitter-desktop --force-device-scale-factor=2 %U