I created inbound route : DID=88040806 custom-App=custom-uniware, at /etc/asterisk/extension_custom.conf, I added:

[custom-uniware]
exten => s,1,Goto(custom-uniware_fax,s,1)

[custom-uniware_fax]
exten => s,1,NoOp(${CALLERID})
exten =>s,2,Set(FAXFILE=/var/log/asterisk/fax/fax_${CALLERID}-${DATETIME}.tif)
exten =>s,3,rxfax(${FAXFILE})
exten =>h,1,System(/var/lib/asterisk/bin/sendfax2.cgi)

then I make a fax, at CLI: 
 -- Accepting call from '0398947736' to '0388040806' on channel 0/2, span  
   -- Executing Set("Zap/2-1", "FROM_DID=0388040806") in new stack
   -- Executing Goto("Zap/2-1", "custom-uniware_fax|") in new stack  
   == Spawn extension (from-pstn, 0388040806, 2) ||exited non-zero on 'Zap/2-1' 
   -- Hungup 'Zap/2-1'

can you help