How do I unplug my kitchen sink?
Here is a good step by step tutorial. https://www.wikihow.com/Remove-a-Kitchen-Sink
Remove as much as possible with a snake or drain cleaning tool. Pour ½ cup baking soda then ½ cup white vinegar in the drain and cover, letting sit for 20 minutes. Boil water, remove cover, and pour water down the drain. You may have to repeat the process.
Have you used a plumber snake?
I regularly run hot water down the drain for five minutes - to help dissolve grease that solidifies once it reaches lower, colder spots in the pipe. I periodically do the baking soda, vinegar and boiling water business. I'd start with this first and repeat a couple of times. If unsuccessful, then I'd use the snake. If still clogged, then llast resort is a plumber unless you can disconnect from under the sink. I found a 10" butcher knife stuck in the pipe in a rental I had.