Why am I getting a 407 Proxy Authentication Required error?

This error means there's a problem with your access credentials or permissions. It is almost always caused by one of these issues:

1. Incorrect Username or Password: Double-check your proxy credentials.
2. IP Not Whitelisted: Your server's IP address is not in the Authorized IPs list for that specific proxy.
3. Zero Balance: Your account balance has run out. Please top up on the Billing page.
4. Proxy is Inactive/Suspended: Check the proxy's status on the My Proxies page.