How Can I Get Javascript Code As Text From .js To Be Inserted Into An Html Page?

I'm new on stackoverflow and I apologize in advance for any wrong way to ask a question.

Solution 1:

by ajax:

    let xhr = new XMLHttpRequest();
    xhr.open('GET', 'test.js');
    xhr.send();
    xhr.onreadystatechange = function() {
        if (xhr.readyState === 4 && xhr.status == 200) {
            console.log(xhr.responseText);
        }
    };