How to enable DTMF tone?

i have a problem because i can not press any number if the ivr on other line is active.
For example when the voice tell me: press 1 for, press 2 for, press 3 for, etc… if i press don’t go.

What i have to set up on my freepbx?

If i add a new extension on “dtmf signaling” in my freepbx i have only 3 choice:

  • rfc4733
  • sip info (application dtmf/relay)
  • in band audio (not raccomanded)

On x-lite or on my ip phone i saw i have RCF2833, maybe this is the problem?
How i can make for use DTMF?
Thank you