Returns the endpoint including its signing secret.
Echo API key — format: echo_<64 hex chars>. Returned once on signup.
Webhook endpoint
"a1b2c3d4-e5f6-7890-abcd-ef1234567890"
"e56b4c35-882d-4604-9944-9763d314ea59"
"https://your-server.com/webhooks/echo"
"whsec_a1b2c3d4e5f6789012345678901234567890123456789012345678901234abcd"
active, disabled "active"
call.started, call.ended, call.summary [
"call.started",
"call.ended",
"call.summary"
]0
"2026-04-12T15:51:59.499Z"
"2026-04-12T15:51:59.499Z"