How to play Bach's vibrato?

These two playing methods are correct and in line with the style of baroque music.

In baroque music, the vibrato of tr tends to start from the top note, that is, it tends to start from E-flat here. Both the playing methods you provide start from E-flat, so they are very good playing methods.

Even if the vibrato of the tr sign does not indicate that the bass is to be played, the bass can be played automatically (that is, the performance is 32 12).

However, since there is no indication to play with lower notes, it is natural to play without lower notes (that is, it can be played as 3232).

In fact, you will find that pianists play this vibrato in different ways. Some pianists play 32 12, while others play 3232. It can also be seen that in fact, this vibrato can be played in two ways, which one depends entirely on your understanding of this piece. In other words, under the premise of ensuring correctness, you can follow your favorite method!

You can ask me again if you have any questions!