Updating Available Columns in Zoho CFM Reports

Updating Available Columns in Zoho CFM Reports

Hi there,

I'd like to customize/update the fields made available in my Zoho CRM reports tab as I realise it is missing some Lead fields. Right now, my Leads have GCLID details, however I am unable to find this field when creating my report under 'available columns'. Is there somewhere I can update the available fields under 'available coumns' for reporting purposes?  

Appreciate your any help and support on this. Thank you!!