Turn Flespi Plugin in async/await

This is an async function. I recommend using [async/await](https://javascript.info/async-await) or even [Promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)

_Originally posted by @BT-Creator in https://github.com/osoc22/project-track-trace/pull/36#discussion_r920201123_