Configuration instructions are not clear

Here is what they say about the configuration:

Make sure you have run npm install
Build the dist directory by running BUILD_MODE=dist npm run build
Establish a link to this repository by running npm link

No problem concerning nodejs installation or linking, but the line "running BUILD_MODE=dist npm run build", I don't know how to run that, it's not a valid command... Maybe I'm just dumb, but if you can explain to me how to do that, I'd appreciate it.

Oh and I'm on Windows 10

Thanks