I'm learning a song on piano (the "Dungeon Theme" from The Legend of Zelda) and I'm having trouble with one particular section because I'm having trouble moving my fingers fast enough to play the passage, and the placement of the keys means I can't just keep my fingers on the keys, because I can't reach all the notes at the same time.
The way I am currently playing the passage is to have my thumb on the F♭, my index finger on the G, then move my hand slightly so I can play the D with my ring finger and the E♭ with my pinky. However, this is very awkward and I am wondering if there is a better way to play this passage. I am pretty new to playing piano so I don't know much about proper technique when it comes to which fingers play which keys or things like that.
In short: What would be the best way to play this passage? What fingers should I use to play each note in order to play it quickly?
Here is the passage in question. The part I am having trouble with is circled in red.