Alarm install on a 57 fiat scudo

[APE37]

Hi there,
hope someone can help. I am trying to get an alarm system fitted to my fiat scudo 57 van. I have brought a canbus 2-1 upgrade alarm and the installer who is coming to install it on Wednesday said that on the canbus system on the van there is something that needs to be activated in order for the alarm to work by a plug in tool. I have contacted fiat and they have said they know nothing about it and passed me to two other companies, one said that there is nothing on the canbus system for that and the other said that there is but it does not affect alarms at it should work it is more to do with sat nav and remote start. The installer has said it won't work until this is done and he will come and install it and leave me with the spec sheet and I will need to take it to a fiat dealer in order to activate the system to communicate with the key. Just wondering if all this is correct what the installer says and if I can't get fiat to help could I take it to an auto electrician to carry the work out or is it something that fiat has to do with specialist equipment?
thanks for all help in advance.