Cannot get proxy script to work on Wordpress site (matomo.js 404 error)

Hi,

I want to connect multiple Wordpress sites to my self-hosted Matomo and I want to use the proxy script. I am using the WP-Piwik plugin and I set everything up correctly - tracking works with the standard script but the proxy script sends no visitor data to Matomo.

When checking my site with the console, I saw this error: (index):123 GET https://trackedsite.com/wp-content/plugins/wp-piwik/proxy/matomo.js net::ERR_ABORTED 404

And indeed, there is no such file in the /plugins/wp-piwik/proxy/matomo.js directory by default. Should something be there? Is any additional configuration needed?

Thank you!

Anyone?

I thought there would be a straightforward solution, seems like a common problem?