DTMF over IMS and the phone will always recieve it

Are there a example when i should send DTMF tones over EC21. I couldn´t recieve any tones when my Phone have enable VoLTE. ( i have test with AT+VTS = “2343” I have Read that we could use RFC2833, but there are no example for that.

How can I fix that.

Can you use AT+QAUDCFG=“voltedtmfcfg” command to Adjust the DTMF audio time in volte mode.
like this AT+QAUDCFG=“voltedtmfcfg”,400,5000