Alarm Wiring for 2017 Kia Cerato Sedan

Dear Forum Members Very new member here, trying to correctly install car alarm system after several electricians have tried but cant get it right. Can you provide techsheet/wiring diagram for KIA Cerato Sedan 2017 model (it might be called Forte in U.S.). We use right hand drive here in Fiji. Installed two alarm systems but having one common issue, meaning theres some messed up wiring or so as two alarm system cant be faulty: once start driving, when i press on brake, the doors should lock automatically. But it doesn't. But if I manually lock doors using the lock button on drivers door, then upon pressing brake next time, the doors do try to lock. So it tries to lock automatically when already locked, but wont do that when unlocked upon pressing brake. Hence am trying to looking for wiring diagram or techsheet to make sense of it. Car has original OEM key fob with central locking. I am adding thirdparty alarm ontop to have alarm upon impact feature. Thank you for any assistance.Tez