Create GL number in Group CoA

Hi,

I am a bit struggling to create G/L accounts, as it comes up with an error message "Corporate Group account not defined in Group CoA"

Having searched on the previous queries in SAP forums, I found the below solution:

"Make sure that you assign G/L account number in group account number field. This is mandatory if you have defined group COA and assigned it to operarting COA. Also make sure that the G/L number you will mention is already created in group COA"

The above solution makes me understand the issue but not resolve. Can you please guide me how to create G/L number in the Group CoA.

Thanks

L