Known a client custom fields in plugin payment gateway

[thenet88]

Hello,

 

I have an Client Custom Fields configured called "Car ID" in my WHMCS script.

 

I'm developing a plugin payment and I want to know the "Car ID" value for the client.

 

How should I have? I tried with $params["clientdetails"]["client_custom_field_carid"];

But I had no success.

 

Thanks you very much.