There are plenty of artists on Twitter who have banner commissions open, but I understand if you want to avoid the website at all costs. Additionally, Twitter has been rumored to shadowban or suppress posts that mention "commission", "price", etc.
I would suggest joining Splatoon discords - the really popular, casual-oriented ones especially - and seeing the promotion or art channels to see if artists are posting their examples or sheets. As an artist, I know I've run to Squid School multiple times to appropriately shill my art in the correct channel!
As Tree mentioned, sendou.ink has a resource to find artists, but I'm unsure how many people still update their profiles to this day.