How can I transfer a live call to IVR

I am not 100% sure about how yo set your IVR and what you want to achieve. But as far as I could try to understand.

You have an IVR menu with prompt message and key presses set. The prompt message is your terms and conditions and one of the key press will transfer the call to a call queue.

There is an incoming call to a user extension, the call is then connected (this is what you call a live call), and now you want to transfer the connected call to the IVR above, then the caller will hear the terms and conditions and can press a key to get the call transferred to a call queue or a user extension?

Is that what you want and if so how did you try it, using the RC app or using API?

Ok, I just tested your use case scenario and it worked perfectly.

While the call is connected, I transferred (blind transfer) the call to the IVR menu by the IVR extension number. Then the call was transferred and I heard the prompt message and I could press a key to connect to a call queue (my IVR is set to press 1 to connect to a call queue).

Since you are doing this using the RC app. You should contact RingCentral customer support to help you checking the settings to make it work.

To perform the same action using RingCentral platform API, you can transfer (blind transfer) an active call to an extension by extension number using this call control API. You can get the active call telephonySessionId and the partyId from the user (the user extension who currently on the call) active calls using this API. When calling the call transfer API, set the right telephonySessionId, the right partyId (the partyId of the user extension, not the other partyId), and the IVR extension number (not the extension id!)

Something like this

async function blindTransferCall(){
  var endpoint = '/restapi/v1.0/account/~/telephony/sessions/'
  endpoint += "ActiveCall_telephonySessionId"
  endpoint += "/parties/ActiveCall_partyId/transfer"
  try{
    var resp = await platform.post(endpoint, {
      extensionNumber : "IVR_Extension_Number"
    } )
    var jsonObj = await resp.json()
    console.log(JSON.stringify(jsonObj))
  }catch(e){
    console.log(e)
  }
}

@Phong Vu Is there any way that we can configure the playback of a recorded message without using a transfer of a call? Our use case is as follows:

We want to playback a recorded message containing some terms and conditions which a customer must either agree to or decline. However, the issue I am running into with the setup as described above is that, once a call is transferred to an IVR, it puts the ring central user back into the call queue where they can then receive calls from other users. Meanwhile, the user whom they were already on a call with will have finished listening to the voice prompt and then be waiting in the call queue again to continue the conversation.