How can I insert a cookie script into my website code?

[Brilant]

I obtained a script for cookies from an external company; they provided me with the URL, which is as follows: <script src="https://bnr.elmobot.eu/M3ygMwULQ4a4LC3QWhUc3/it.js"></script>. I would like to add it to my website www.secretsbyglammy.com, but I'm not sure how to include it in the code. I've already tried using some external applications, but it doesn't work. Do you have any advice? Thank you in advance, and I apologize for the delayed response