How can I find the "helpCenterId" ( or where is it ? )

How can I find the "helpCenterId" ( or where is it ? )

Hello, We want to create an api request based on documentation found on :
https://desk.zoho.com/DeskAPIDocument#Contacts#Contacts_Invitecontacttohelpcenter
How can I find the "helpCenterId"  ? Where is it located in Zoho Desk ?
Thank You