Zapata.conf:

[channels]
echocancel=128
echocancelwhenbridged=no
echotraining=yes
rxgain=1.0
txgain=1.0
usecallerid=no
;callprogress=yes
busydetect=yes

context=Reception
signalling=fxs_ks 
group = 1
channel => 1-4,25-28   


Extensions.conf context:

Does not work:
[outbound-local]
exten => _NXXNXXXXXX,1,Macro(zap-out,${EXTEN})    

Works:
[outbound-local]
exten => _NXXNXXXXXX,1,Answer
exten => _NXXNXXXXXX,2,Macro(zap-out,${EXTEN})