Running a script added after the page has loaded

I need to add the pages later for my project, but after adding the script tag at the bottom is not executed.

Main

const fetch = (url, call) => {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
call(xhttp);
}
};
xhttp.open(“GET”, url, true);
xhttp.send();
}

const UpdatePage = page_name => {
fetch(`/app/${page_name}`, (data => {
App.innerHTML = data.responseText;
}))
}

Code of new page

<div>
<%= showId %>
</div>

<script>console.log(“Welcome to somewhere”)</script>

Page loads sucessfuly but the javascript not be executed. How i can execute the script tag on new page added?