In your vs code environment, search in the extensions tab for and install the one titled "Remote - SSH".
Use the shortcut ⌘^P to bring up the VS Code command menu. From there typing SSH should reveal an option titled "Add New SSH Host". You'll then want to enter the following: ssh.rc.byu.edu. An option box will pop up in the bottom corner, you'll want to hit connect there.
You can then once again use ⌘^P to find possible SSH commands and this time you'll want to select hte option titled "Connect to Host" where you should see a remote host available to connect to. A new VS code window should open and you'll be asked to enter your supercomputer account password as well as a verification code. After doing so you'll be accessing the supercomputer and can open and modify all files using the VS code text editor as well as access the terminal as one normally would.