Phone Number Not Registering to Cal.com From Retell AI

Hey guys i am having trouble with getting my retell AI agent to send the customers phone number to make.com. I am using Retells personal cal.com intergration to book appointments, see screen shot bellow.

When i just make the email and Name a requirement on cal.com, the appointment goes through.

But..

When i set phone number as 'required' on cal.com, the appointment dose not go through and the phone number dose not go through either.

I keep getting this error code.------>

{"error":"Error calling Cal Booking API: Axios Error: error code: ERR_BAD_REQUEST, error message: Request failed with status code 400\nresponse status: 400\nresponse data: [{\"status\":\"1\",\"timestamp\":\"2\",\"path\":\"3\",\"error\":\"4\"},\"error\",\"2025-11-02T03:12:29.748Z\",\"/v2/bookings\",{\"code\":\"5\",\"message\":\"6\",\"details\":\"7\"},\"BadRequestException\",\"Missing required booking field response: phone - it is required by the event type booking fields, but missing in the bookingFieldsResponses. You can fetch the event type with ID 3734045 to see the required fields.\",{\"message\":\"6\",\"error\":\"8\",\"statusCode\":400},\"Bad Request\"]"}

I have told my agent in the prompt to set phone number ID to "phone" as that is the identifier i have named it on cal.com. see screen shot above.

So for some reason, Cal.com isnt clocking or taking in the customers phone number. If anyone can help me out with this it would be a really big help. Thank you 🙏

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