@jtohme This error message was given specifically to warn you that the plugin would not work as it requires the REST API to be available for gathering the URL Metrics. Have you turned off the REST API from being accessible to unauthenticated users? If so, then the plugin is working as expected. This is explained in the plugin’s description on the directory:
Your site must currently have the REST API accessible to unauthenticated frontend visitors since this is how real user metrics are collected about pages on your site; nevertheless, exploration is underway for providing alternative mechanisms for collecting the metrics.
So what you’re experiencing does not seem to be a bug. I’d appreciate it if you could revise your review.
@jtohme It’s not actually for developers only. Do you have a plugin that is disabling the REST API for frontend visitors? That’s the issue here. It should work out of the box otherwise.
The plugins Image Prioritizer and Embed Optimizer use Optimization Detective as a dependency plugin. The expectation is that regular users (non-developers) would install these plugins along with Optimization Detective without needing to be a developer. But as mentioned above, if you disable the REST API then it won’t work. But this is explained in the readme (including the readme for Image Prioritizer).
