Import a .js file into another (JSLINT doesn’t recognize the “Import” key word)

I am trying to import a .js file into antoher.js file. JSLint is throwing errors and doesn’t seem to recognize the “import” statement

The errros

import "./Scripts/dompurify/purify.min.js";

(function ($, constants, appUtilities, window, confirm) {
    var DATE_PATTERN = /^(?=d)(?:(?:(?:(?:0?[13578]|1[02])(/|-|.)31)1|(?:(?:0?[1,3-9]|1[0-2])(/|-|.)(?:29|30)2))(?:(?:1[6-9]|[2-9]d)?d{2})|(?:0?2(/|-|.)293(?:(?:(?:1[6-9]|[2-9]d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))|(?:(?:0?[1-9])|(?:1[0-2]))(/|-|.)(?:0?[1-9]|1d|2[0-8])4(?:(?:1[6-9]|[2-9]d)?d{2}))$/, GTSelectedTestId,
        ADDRESS_PATTERN = /^[0-9a-zA-Z.'@#%&/-s]*$/;

    function mutexCheckboxSelection(mutexCheckboxes, event) {
        if (!mutexCheckboxes || mutexCheckboxes.length < 2) {
            return;
        }