[Freeswitch-users] spandsp_start_fax_detect how to use?

Hello, I have one DID that I would like to detect the tone 1- if fax goes to extension 1111. 2- If it is is not fax then t goes to extension 2222 How do that using spandsp_start_fax_detect ? I am looking for the Inbound dialplan Thanks in advance, George