Try below in your src/polyfills.ts or you might need to use your angular.json file to add this. I am not sure though because this is a straight forward thing. Anyway read this as well. https://frontendinterviewquestions.medium.com/can-we-use-jquery-in-angular-d64e7d4befae https://www.geeksforgeeks.org/how-to-use-jquery-in-angular/

import * as $ from 'jquery';
(window as any).$ = $;
(window as any).jQuery = $;