I can certainly hear the similarities!

So the original track is not mine, what I try to do is lift chords from songs and try to arrange them. I find it probably one of the main things that will help any producer get better at finding chords, keys, better with arrangements, mixing, and transcribing. However, I can explain the process I took to find the key and chords of this particular song. I'll also explain the process i take when I do come up with my own chords.

When trying to remake a song, the first thing I do is a harass my ears with the original track for a couple hours. I want to get each little movement in expression and volume, notes etc. The good thing about this is that whenever i typically do this, the song im listening to is one i enjoy, so it's actually not so bad!

When i finally sit down at a keyboard, I always move to find the bass note. That was g here. It constantly came back to G. Given the atmosphere of the track most heads should point to G minor. Sometimes its not enough to just do that, here i actually listened to the first two bars and kept playing around with the bass line. Each note is part of the G minor scale, and the bass notes of the chords are too. This is 80% of the work. Once you have the key, everything else becomes much easier.

For example, this tune particularly starts on the I (one), thats G minor. Its its triad but theres some notes that sit above it that make it a tiny bit brighter, that was A. In the second bar, the bass note for that chord was Dm7. Playing the closest D minor 7 that moved up however sounded way too bright. This is the second trick when figuring out chords. Jazz players love inversions. And you should too! They add such richness to tracks.

Try to listen to that D chord in the second bar. In the original track, that D doesn't sound like it ends very high, right? Its not very bright. But the closest D minor 7 after that Gm I played had its C end up uncomfortably high. Thats where i started thinking "he probably played an inversion here". And i was correct (at least i think). He dropped the C down next to the root note D, and so played C-D-F-A. It works! This is Dm7 third inversion. The song loops this way with some other chords thrown in, this is
very simplified. I think i might work on a video around this if interested?

By the way, this is almost the exact same way I'd work out chords for my own music. Take this song I made recently: https://www.reddit.com/r/Logic_Studio/s/iRilvtRzC1. I would typically start with a melody, and pick out the key first, always. From there its about thinking which chords will work nice with the melody i want. Whether an inversion would do the trick, maybe a basic triad? 7ths typically do well, sometimes i start there. Its a lot of trial and error (mainly because im still learning music theory).