HTTP request fails with 403 error when performed through certain User-Agents to website in Plesk

Symptoms

• HTTP request performed against a WordPress site using certain User-Agents fails:

  "GET /site/ HTTP/2.0" 403 162 "-" "python-requests"

• Issue can not be reproduced by accessing website using different HTTP-clients or web-browsers.

Cause

WP Toolkit Security measurement "Bot protection" prevents multiple user-agents from connecting to the site.

Resolution

1. Log into Plesk.
2. Navigate to Domains > example.com > WordPress > Security page.
3. Mark the checkbox next to Enable bot protection.
4. Press Revert button.