Google ads test manager account

I cannot find anywhere how to add a manager account and specify it is a test one. How do I create TEST manager account? -- -- =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ Also find us on our blog: https://googleadsdeveloper.blogspot.com/ =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ Y

TargetingIdeaService

Hello, I want to use the TargetingIdeaService, but form a server to server connection. I see that connecting service account is only available for Ad Manager api, but that does not allow me to use the TargetingIdeaService. Also, Ads Api, seems to be only for desktop and web apps. How is the bes