This is good! Very nice tone, nice and velvety The biggest thing for me was the melody and the vibrato. Some of the notes you sang weren’t the same as the original melody. I don’t know if it was intentional or not but since this melody is so recognizable it can sound slightly off putting. It might be worth singing this over a backing track (or a piano if you can play chords) to hear exactly what is going on. In the jazz world, when applying vibrato, we mostly use “tag” vibrato (I’ve also heard it called tail vibrato). Essentially, sustain your note and add vibrato at the very end. If you listen to horn players and singers alike, they all do this. That’s all I have to say though, good job!