Depending on the details in each of the layers[1] you might be able to spoof traffic towards it to trick it things.
you may need to try MITM the certs/key exchange stuff[2], hopefully they have a broken implementation that doesnt validate signatures etc.
[1]: https://www.bmc.com/blogs/osi-model-7-layers/
[2]: first promising hit when i googled: https://gbhackers.com/mitm-attack-https-connection-ssl-strip...