Image tracking don't work

I want to count users that use my bookmark in my Piwik/Matomo instance.

This is my code:

x = new Image();
x.src = '' + location.href;

The problem is that when I open the statistic for today I don’t see website with bookmark or reference on which the script was executed. I did this in incognito mode, so there was not cookie that disabled tracking for my browser. I’ve also tried in guest account in Chrome browser that don’t have any extensions installed (same as in incognito mode). In dev tools I’ve got request that returned 200 error code.

The bookmark is REPL for Scheme language, so it’s more likely be website that have Scheme learning resource or YouTube with video about Scheme. I think it’s not the problem that I will track the url when bookmark was executed, there will be no information about the actual user so I think this is fine.