rollup (still) not working - cannot find module 'node:process'

I downloaded the packaged repository, unpackaged it, installed nodejs and npm through nvm (latest stable version of nodejs 12), installed rollup, ran the command npm install in the directory where I unpackaged the repo, ran rollup -c, and I get this error message:

node:internal/modules/cjs/loader:927
  throw err;
  ^

Error: Cannot find module 'node:process'
Require stack:
- C:\Users\av3st\.nvm\versions\node\v15.14.0\bin\node_modules\rollup\dist\bin\rollup
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:924:15)
    at Function.Module._load (node:internal/modules/cjs/loader:769:27)
    at Module.require (node:internal/modules/cjs/loader:996:19)
    at require (node:internal/modules/cjs/helpers:92:18)
    at Module.<anonymous> (C:\Users\av3st\.nvm\versions\node\v15.14.0\bin\node_modules\rollup\dist\bin\rollup:16:19)
    at Module._compile (node:internal/modules/cjs/loader:1092:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1121:10)
    at Module.load (node:internal/modules/cjs/loader:972:32)
    at Function.Module._load (node:internal/modules/cjs/loader:813:14)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:76:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    'C:\\Users\\av3st\\.nvm\\versions\\node\\v15.14.0\\bin\\node_modules\\rollup\\dist\\bin\\rollup'
  ]
}

I tried searching for this error, but all I got from stackOverflow is that I should try and change the NodeJS version. I can't say I've done everything I can because honestly, I'm quite tired at this point, so I'll just ask people who are more experienced than me (I haven't written anything with NodeJS in my life and I'm just using it to try and code Screeps in TypeScript because I despise JavaScript).

Sorry if I came off rude, I really am quite tired and cranky. Thanks in advance for any ideas.

screepers / screeps-typescript-starter

rollup (still) not working - cannot find module 'node:process' #172