Doesn't work strings.includes etc?

Question

JavaScript

Tutorial https://www.youtube.com/watch?v=NQ2i...i8o-_c-9Vva_W0 where the dude does the crm on the vue and the firebase. Passed half. Everything seems to be normal, but every now and then I come across incomprehensible errors when compiling or displays:
console.log("1234 5678".includes("1234"))
Object.keys(_r).length

WAIT  Compiling...                                                                                                                           21:36:20
 98% after emitting CopyPlugin

 ERROR  Failed to compile with 2 errors                                                                                                       21:36:22
These dependencies were not found:

* core-js/modules/es6.string.includes in ./src/main.js
* core-js/modules/es7.array.includes in ./src/main.js

To install them, you can run: npm install --save core-js/modules/es6.string.includes core-js/modules/es7.array.includes

Trying to follow the advice gives:

npm install --save core-js/modules/es6.string.includes core-js/modules/es7.array.includes
npm ERR! code ENOLOCAL
npm ERR! Could not install from "core-js\modules\es6.string.includes" as it does not contain a package.json file.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\user\AppData\Roaming\npm-cache\_logs\2019-07-07T18_46_12_187Z-debug.log

what is this? Babel's babism? how to deal with it?
package.json :

{
  "name": "vuecrm",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build"
  },
  "dependencies": {
    "core-js": "^3.1.4",
    "es6": "^0.0.7",
    "firebase": "^6.2.4",
    "materialize-css": "^1.0.0-rc.2",
    "register-service-worker": "^1.6.2",
    "vue": "^2.6.10",
    "vue-router": "^3.0.3",
    "vuex": "^3.0.1"
  },
  "devDependencies": {
    "@vue/cli-plugin-babel": "^3.8.0",
    "@vue/cli-plugin-pwa": "^3.8.0",
    "@vue/cli-service": "^3.8.0",
    "node-sass": "^4.9.0",
    "sass-loader": "^7.1.0",
    "vue-template-compiler": "^2.6.10",
    "vuelidate": "^0.7.4"
  }
}

Answer 1

Try installing [email protected] instead of 3. Sometimes authors forget to specify the version and end up downloading an incompatible package.

npm un -S core-js
npm i -S  [email protected]