manually delete analytics.js

Hello,
I am writing to you because I have this problem with analytics.js and even your plugin could not remove this problem. I wanted to ask if it is possible to manually delete this analytics.js file. Weird is that I have nowhere installed plugin on Google Analitics and my page is not associated in any way with Google Analitics. Why is this code still coming out doing tests with GTmetrix or google speed test? Some time ago I had installed on my web the plugin Google Analytics. Where this analytics.js file is located? I would be grateful for your help