One account works everywhere. Platform Admin access is granted by permission.
Open the team web app (schedule, roster, injuries, stats) and manage billing.
View all teams, manage platform admins, and manage user accounts.
If you don't have platform access, you'll see "Access restricted".
Tip: if you get bounced back to sign-in inside the mobile web view, it usually means cookies were blocked. Try "Open in browser" or allow cookies.