Attempting to create a Cosmos DB in ACG sandbox. Deployment fails and output response states:
"message": "Free tier has already been applied to another Azure Cosmos DB account in this subscription. To apply free tier to this account, you can select another subscription for this account or delete the existing free tier account. You can have up to one free tier account per subscription.rnActivityId: ae8c9617-cce1-45a9-afee-d432d66d8eda, Microsoft.Azure.Documents.Common/2.14.0"
When creating Cosmos DB, use the same resource group as your lab provisioned resource group and select Do Not Apply on the Apply Free Tier question. I would also choose disable on the geo-redundancy option and have the backups be locally-redundant for practice. (In a true production environment you may want different options depending on the scenario). That will enable the practice deployment to succeed.