If the exact same request is working in the browser but failing for the Python program, they're probably not tunneling all traffic on their computer through a V

If the exact same request is working in the browser but failing for the Python program, they're probably not tunneling all traffic on their computer through a VPN, but have only configured the browser to use a proxy. You should be able to make the requests library use the same proxy. IIRC, there's an environment variable you could set to achieve this without code changes.