SAP API HUB: 401 on-premise call

[DamianKolasa]

Hello,

I play with trial version of integration suite. My task is to evaluate possibilities with on-premise systems integration. I was able to configure SAP cloud connector to point to our on-premise HANA system, configure it in subaccount's destinations and utilize in api.hub:

1. On-premise system is configured as data provider(all connection tests are successful);
2. I'm able to create API based on a provider (service catalogue is read properly from on-premise system);
3. API generates available resources, i.e.:
   

Problem appears when I try to test one of these resources. I'm always getting 401 Unauthorized. There're no logs on cloud connector side, so there's a problem with communication API->BTP or BTP->SCC (I guess). I can't get any extra information about it, all I have is HTTP code and HTTP headers:

I tried to switch between HTTP and HTTPS connections, and try different authentication methods (basic, principal propagation, none...) - no effect at all. I can reach particular service directly from web browser using our on-premise URI and technical user I used for connection.

Thanks in advance for any hints.

BR,
Damian