Ok, so I tried installing from my phone but it didn't detect the pixel 6A (tried with both Brave and Chrome). I then moved to my Fedora latptop, but got the "Error: Failed to execute 'claimInterface' on 'USBDevice': Unable to claim interface" error. After getting some help on the Matrix Channel I managed to install it with a Windows laptop.
So my advice for other novices like me would be to use a Windows machine. It takes about 45 minutes depending on the internet speed, but it's probably the easiest and safest way.