Typescript cant find module

I'm trying to import a module with Typescript on Visual Studio 2019.

import * as Highcharts from 'highcharts';(<any>window).Highcharts = Highcharts;

Results in:

Error TS2307 (TS) Cannot find module 'highcharts'.
Error TS2307 Build:Cannot find module'../node_modules/highcharts'.

This is my tsconfig.json

{"compilerOptions": {"noImplicitAny": true,"noEmitOnError": true,"removeComments": false,"sourceMap": true,"target": "ESNext"  },"include": ["**/*"  ],"exclude": ["node_modules","wwwroot"  ],"compileOnSave": true}

This is my packages.json:

{"version": "1.0.0","name": "asp.net","private": true,"devDependencies": {"gulp": "4.0.2","del": "5.1.0","highcharts": "8.0.0"  }}

If I look under dependencies => npm, highcharts is there. If I look in my node_modules folder, highcharts is there.

What am I missing? I'm new to using modules in typescript but everything I find on google seems to look like my setup.