jQuery script not working between script tags in HTML

I have a jQuery solution that works on other webs but it doesn't work on my website. It is situated between standard html script tags. Do you know what could be wrong ?

Hi,

Check if you have correctly included jQuery library in your code. It should be located before the jQuery script:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
alert('jQuery script works');
});
</script>