In this documentation, we can check how to enable proxy in Joomla.
1) Login to Joomla admin panel.
2) Go to ‘System’.
3) Click the option ‘Global Configuration’.
4) Go to the tab ‘Server’.
5) Locate the section ‘Proxy Settings’.
6) Change ‘Enable Proxy’ to ‘Yes’ and enter the details.
7) Click the button ‘Save’.
Also provide the Proxy username, port and host details. That is how we can enable proxy in Joomla.
If you need any further help please reach our support department.