Causes of 403 Forbidden
Often, HTTP 403 forbidden errors are caused by an access misconfiguration on the client-side, which means you can usually resolve the issue yourself.
A common cause of these errors is the file or folder permission settings, which control who can read, write, and execute the file or folder.
There are two possibilities in this case: either the website owner edited the settings so that you couldn’t access the resources, or they didn’t set the correct permissions.
The second common cause is corrupt or incorrect settings in the .htaccess file.
Other than those two common causes, here are some other possible triggers for the error:
Missing index page – the website’s homepage name is not index.html or index.php.
Faulty WordPress plugin – if a WordPress plugin is not configured correctly or is incompatible with another plugin, it may trigger the 403 errors.
Wrong IP address – the domain name points to a wrong or old IP address which now hosts a website that blocks your access.
How to Fix the 403 Forbidden Error
Since the HTTP 403 forbidden error is closely related to file access permissions, this will be the main focus of the following methods to solve it.
Please put index.html or index.php file in your website's homepage.