Unable to refer to method `db.start Session ()` in mongoose, mongodb

When I try to refer to db.startSession () I have an error db.startSession () is not a function. In console.log I put db and I put logged variable below. Why can’t I refer to startSession()? connection …

How to get a value in async function as soon as possible?

I’m working with Ethereum blockchain, but my problem my is JavaScript (async, await function). Here my code simplified: In my html App.addBlockChain(n.username,n.first,n.last,n.email).then(value => …