When transferring projects over to DoiT Billing, the UI shows the following example gcloud command to do this:
To add the service account to your organization:
for org in $(gcloud organizations list --format="value(name)"); do gcloud organizations add-iam-policy-binding $org --member='serviceAccount:sa-afw6apjtjqhdvz7wjcnr-4879@me-doit-intl-com.iam.gserviceaccount.com' --role='roles/billing.admin'; done
However, when you click the copy-paste button that puts this into your clipboard, a more optimized command is placed there:
gcloud organizations add-iam-policy-binding $(gcloud organizations list --format='value(name)' --limit 1) --member='serviceAccount:sa-afw6apjtjqhdvz7wjcnr-4879@me-doit-intl-com.iam.gserviceaccount.com' --role='roles/billing.admin'
Looks like the UI command needs to be updated to reflect this