Hello, I've followed the tutorial for connecting Zadarma and Vapi but for some reasons in Vapi it says the customer ended call (3 seconds) but it never called. The phone number says busy when I ring it.

Thanks for sharing this, I understand how frustrating it is when calls end instantly without ever ringing, especially since your VoIP test works. This usually points to a signaling or routing issue between Zadarma and Vapi rather than a credential problem. I can help you trace where the call is being dropped by reviewing your SIP setup, call logs, and Vapi events. Are you using direct SIP trunking or routing through Zadarma PBX, and do you see any error codes in their logs? @Deathx

@Deathx hi could you please provide the call id where this issue occurred?