Explanation

Sensor data must be stored in a Cosmos DB named treydata in a collection named SensorData Sensors must have permission only to add items to the SensorData collection Box 1: Resource Token Resource tokens provide access to the application resources within a Cosmos DB database.
Enable clients to read, write, and delete resources in the Cosmos DB account according to the permissions they've been granted.
Box 2: Cosmos DB user
You can use a resource token (by creating Cosmos DB users and permissions) when you want to provide access to resources in your Cosmos DB account to a client that cannot be trusted with the master key.
References:
https://docs.microsoft.com/en-us/azure/cosmos-db/secure-access-to-data