Welcome Akira!
There’s only one concrete suggestion that we can make for trying to get mrview to run, which is documented in this Wiki page. If Point 3 there does not solve the issue, the problem is really one of local hardware or OS, so you might be better off seeking local IT support.
Also, how do you test if MRTrix is installed properly?
If you are able to execute mrview by simply typing “mrview” (or any other MRtrix3 command) at the terminal, that’s just about the extent of installation verification. We try to not have dependence on a wide range of installation trickery; if the commands appear in your PATH, they should work.
Cheers
Rob