I’m facing an issue while connecting Discourse to WordPress using the Discourse Plugin. I’m running Discourse on a Digital Ocean droplet. The setup was performed exactly as mentioned here (discourse/INSTALL-cloud.md at master · discourse/discourse · GitHub). The droplet itself sits behind CloudFlare and HTTPS was setup using Let’s Encrypt (using Setting up HTTPS support with Let's Encrypt). The WordPress site is deployed on SiteGround, also behind CloudFlare.
When I add the forum’s root address, API key and administrator username in the plugin settings, in WordPress’ console, it still keeps saying “You’re not connected to Discourse”. Upon further investigating I’ve found that this particular request
/site.json%20?api_key=[FILTERED]&api_username=<username> is returning 403 Forbidden even with a fresh, valid API Key and a valid administrator username.