I have configured the URL in Blocs, and you can verify that my website indeed works and WP is there when navigating to the URL. I also have the Blocs plugin installed in my WP website.
How does the Blocs app access the data? Is there no username/password needed? Is there any “dark” setting I should check on my server? Maybe the name of my DB is non WP-standard?
Thanks! That gave me a great hint on where to look. I found this error on the WP admin panel, under Tools > Site Health, saying that “the authorisation header is missing” and that without it, some apps couldn’t connect to the site.