According to highcharts readme you need to import it something like this
import Highcharts from 'highcharts';
then you need to update your tsconfig.json
file
{"compilerOptions": {"allowSyntheticDefaultImports": true,"esModuleInterop": true,"baseUrl": "./","module": "es6","moduleResolution": "node","target": "es6","paths": {"https://code.highcharts.com/es-modules/masters/*.src.js": ["node_modules/highcharts/*.src" ] } }}
check thishttps://github.com/highcharts/highcharts#typescript--umd