GAB import contacts

How can I import my contacts to the GAB?

What do you mean with “import”? Are you looking for https://wiki.z-hub.io/display/ZP/Configuring+GAB-Sync+for+Kopano+OL+Extension?

I will only store contacts in the gab. And so i will import the contacts from one user to the gab.

You seem to have a misunderstanding what the gab is. See my reply to your other topic.