Constant TELEPORT_APP_PROTOCOL 

const TELEPORT_APP_PROTOCOL: &str = "http";

The internal HTTP endpoint is plain HTTP, not HTTPS. Set explicitly rather than relying on Teleport’s port-name heuristic to guess it.

NOTE: the agent applies this to every port it selects, so it is only safe alongside TELEPORT_APP_PORT. On its own it would force http on all four ports and register four apps.