Hi. Plumber here. Forget all those chemical drain cleaner ideas. Most are garbage. The active ingredient is hype. By the time it reaches the clog, the hype will be too diluted to do anything. If it doesn't work and you call a plumber, they may bill you extra for some chemical getting on their boots/pants.
Your best bet is to unclog it with a drill-powered auger like this:
Whether it's you or a professional plumber who does the unclogging.
The most likely culprit is food that went through the garbage disposal. No matter how powerful your disposal, no matter how much it cost, no matter how much it "should" work, there are
plenty of things that should never go through it. Things like potatoes, celery, corn husks, rice, pasta of any type, all kinds of things. IMHO, disposals are largely useless. Homeowners think it's an electric trash can.