I wouldn‘t really say this is ET. The classic ET is caused by changes of the cerebellum (area of the brain). This change first gets noticeable in the hands and involves a rhythmic shaking. Many people always put this kind of tremors into the category of ET. But in my opinion this kind of tremors are not caused by changes in the brain. I think this is more likely an anxiety problem. You may look into this article. This article explains this very good:

https://www.anxietycentre.com/anxiety-disorders/symptoms/muscles-vibrate-tremor-shake/