Hi @saptoafr26,
When there’s a HTTP 403 (Forbidden) status response from the server it usually means that there’s something preventing WordPress Popular Posts from communicating with the REST API (normally, a conflict with another plugin.)
The following FAQs cover the majority of the cases when this happens so please have a look and report back your findings:
If you’re using WooCommerce on your website (doesn’t seem to be the case but though I’d mention it anyways just in case) right now there’s a known compatibility issue that the WC team is currently working on: WooCommerce breaks other plugin’s ability to send POST requests to REST API (rest_cookie_invalid_nonce).
About the long response time, you’ll want to read this FAQ as well: WordPress Popular Posts is slowing down my website, what can I do?
If you have any other questions don’t hesitate to ask.
