Helping a student connect Zadarma to VAPI as a BYO SIP trunk and he keeps hitting a wall at the final step.
The problem:
Every time he tries to save the SIP trunk in VAPI, he gets the same error:
"Failed to create SIP trunk credential."
No variation and no additional detail from VAPI.
What he's already tried:
- Bought a fresh Zadarma number
- Set up the SIP trunk in VAPI with Zadarma username + password credentials
- Tried multiple different username/password combinations
- Searched YouTube and forums — only found year-old threads with the same error and no resolution
What we're looking for:
- Anyone who has successfully connected Zadarma to VAPI as a BYO SIP trunk
- Any known quirks with Zadarma's SIP credentials format
- Whether "Use SIP Registration" needs to be toggled on or off for Zadarma specifically
If you've solved this or have a working Zadarma + VAPI setup, drop a comment or DM me 🙏