What steps should I take if none of the above solutions resolve the 403 Forbidden error on my Safari iPad?

If you've tried all the above steps and the error persists, it's highly likely a server-side issue. Contact the website's support team and provide them with details about the error, your iPad model, and your approximate location. They may be able to identify and resolve the problem on their end. You can also try accessing the website from a different device or browser to confirm if the issue is specific to your iPad.