How to use GTM topology via ISP link which not included?

Hi

We want to LB GTM using topology method via ISP link.

But our ISP link is not included in ISP selection. It's have only AOL and some china ISP. Didn't have my country ISP.

How Can I LB topology via ISP link which not included in selection?

Thank you

PS. I saw we can select "geolocation ISP" but it's blank space and I didn't know what to do with it.