First step is to get a calibration target that is supported by dcamprof - The X-Rite/Calibrite ColorChecker is the gold standard here. @kmilos already posted the link to RawTherapee’s color profiling document.
Per the linked article, you will need to shoot the target in direct noon sunlight, and also lit by a proper tungsten bulb (not fluorescent or LED, even a high-CRI one, although in the short term that’s better than nothing…) - the latter can be difficult in some countries. Tungsten bulbs are hard to find in the US, but they are still carried in Lowes or Home Depot if you spend a few minutes browsing the shelves. I bought a bulb and a bulb holder that I use only for profiling tasks.
If you encounter any issues with the process (especially if you have a fixed-lens fisheye camera but that does not seem to be the case here), we can help you if you encounter any snags - but the first step is to get a target.
I plan on updating that document later to hopefully resolve a few minor ambiguities, but right now there’s talk of replacing rawpedia with a different document management system - An update on Rawpedia
I’ve profiled multiple cameras (the included RawTherapee profiles for Sony A6300, A6500, and A7M4 were all either done by me or from test shots provided by me, and I also have a profile for the Xiaomi Mi Sphere 360 that many people have used) including fixed-lens fisheye cameras, so can help you with the details if you hit snags - but you need a target and appropriate light sources first!