That's a remarkable coincidence, in the last couple of weeks I've been experimenting briefly with shooting RAW on our Sony RX100 III. We bought it a couple of years ago and have always shot in Extra-fine JPEG on backpacks up to now. I decided to investigate RAW support particularly for night sky photos since exposure adjustment is better dealt with in RAW before arriving in GIMP for further tweaking.
I don't know your system setup, so first crucial thing: which operating system and which version of GIMP?.
For our Sony I did get Darktable to work in the end but I find the interface spectacularly unintuitive, I don't like it!.
The much preferred way is to use
ufraw, it operates as a stand alone utility or, better, as a GIMP plugin. At the moment I can't try it for highly technical reasons but I'm working on it. Regardless of system, everything depends on whether it supports your camera model.
One hurdle I wasn't expecting with the Sony is the need for lens correction. The RAW image opened in Darktable has severe barrel distortion, fortunately the lens-correction options include one that works perfectly with the RX100.