I'm not a fan of everything you see on YouTube....
Try this - set your mic gain high - say 75. Set the processor to zero. Speak into the mic and adjust the AMC control so that the ALC meter deflects to three quarters of the ALC Bar (~S8) with normal speech. Then back the mic gain down until the ALC meter deflects just a tiny bit less than the previous step. Then add in 10 to 15 db of compression with the processor control. Typical values values for AMC are 40 to 60 and 25 to 35 for the processor. Where the mic value ends up depends on your mic, voice and how far from the mic you are. Generally in the 25 to 75 range. The best way to do all this is looking at your RF envelope on a scope. Of course, I just saw a YouTube that pretty much says RF envelope testing is useless. It is not.
BTW - any ALC meter deflection means the RF envelope is reaching full PEP output. The RF meter on the FTdx-10 is an averaging meter with no peak hold - it will typically show 35W or so with normal speech on SSB. Higher if you run the processor up higher, but probably never more than 50W.
Did I mention RF envelope testing with a scope? It's the best PEP "meter".
Dave