NPM node-sass installation fails

You're using Node 12, and node-sass needs to be at least 4.12 to support that version https://github.com/sass/node-sass#node-version-support-policy

If anyone runs into this lately... the easiest fix is to replace node-sass with just sass in your dependencies. It's the more recently maintained version and I only had to change 1 line of code with how it's initialized and all of my existing code was already compatible.

There are more details at https://sass-lang.com/blog/libsass-is-deprecated under How to migrate.