error when running start_server.js on replit

[gulkily]

~/LessonAug21/thimble$ node start_server.js
node:internal/modules/cjs/loader:988
throw err;
^

Error: Cannot find module 'luxon'
Require stack:

• /home/runner/LessonAug21/thimble/start_server.js
  at Function.Module._resolveFilename (node:internal/modules/cjs/loader:985:15)
  at Function.Module._load (node:internal/modules/cjs/loader:833:27)
  at Module.require (node:internal/modules/cjs/loader:1057:19)
  at require (node:internal/modules/cjs/helpers:103:18)
  at Object. (/home/runner/LessonAug21/thimble/start_server.js:12:22)
  at Module._compile (node:internal/modules/cjs/loader:1155:14)
  at Object.Module._extensions..js (node:internal/modules/cjs/loader:1209:10)
  at Module.load (node:internal/modules/cjs/loader:1033:32)
  at Function.Module._load (node:internal/modules/cjs/loader:868:12)
  at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/home/runner/LessonAug21/thimble/start_server.js' ]
  }

[gulkily]

workaround: npm install luxon

(also missing: git module)