Use Python$3$ to implement the following.

app$2$: Should be receiving the secure transmission payload from app$1$ using TLS$.$ It will then hash the JSON payload and append it to the message $($HMAC SHA$-256)$ and use secure SFTP to send the payload to a receive folder which app$3$ will verify the file has been received. The same key will be stored on app$2$ and app$3$ needed for the HMAC. All workflow actions pass or fail will be logged into the activity MongoDB NoSQL database with an identifier and timestamp. Unit tests will confirm all methods are functional.

app$3$: will receive the secure SFTP payload from app$2$ using SFTP and verify the hash matches using HMAC SHA$-256.$ It will email to the team members the payload using threading to their email addresses. All workflow actions pass or fail will be logged into the activity MongoDB$$NoSQL database with a timestamp.$$Unit tests will confirm all methods are functional.

app$5$: will receive all the log requests and put them into the MongoDB database. Please use the Python$3$ logging class.$$There should be method handlers for the pass$$and fail.$$Unit tests will confirm all methods are functional.