How to add a DTMF before call end?

[midwest1]

I have some extensions that 99% of the time they receive a call from certain safety devices where these extensions must dial 9 and end call (This DTMF will bring those devices to a disarm and reset the system)- My problem is since many users are not hanging out the call properly my idea is every time they end a call PBX could sent a DTMF "9" tone automatically when user hang up a call.
I never used call flow designer. I watch some videos but not sure if CFD can get this idea done. Please share some ideas how how could I accomplish this solution.

 

[Evolute IT]

Not possible at all. CFD cannot do stuff for other calls.

 

[edossantos]

Also, not even possible if the call is connected to the CFD app, because an app can only receive/detect DTMF tones, but not send them.

 

[midwest1]

Thanks for both answers. I'm a little stuck trying to resolve a fault of several end users putting a safety system in jeopardy just because they don't hang up calls properly. I need to find a way to perhaps push a pre recorded DTMF at the end of the call.