I am looking in the Apps → Manage private apps → {APP Name} → Admin API section.
Ah… I didn’t realize it was a private app.
From the https://shopify.dev/apps/subscriptions/contracts page:
The requirements for building an app that uses subscriptions depends on the type of app that you’re building. Private apps can’t access Subscription APIs. Public and custom apps need to request access to the appropriate protected scopes through the Partner Dashboard.