Bar Keeper's Friend. I like the powder. It does come in a liquid. Sprinkle a good amount in the bottom, wet a paper towel, and scrub in a circular motion. Rinse and repeat until all the burnt is gone, then wash as usual with soap.

Do not put the Bar Keeper's on and leave it to soak. That won't help and isn't good for your pan. If you get tired, just rinse well, fill with plain water, and take a break. Then start back. It will be like new.

https://www.barkeepersfriend.com/cleaning-products/

This is the one I use. https://www.barkeepersfriend.com/cleaning-products/cleanser-polish/

Put an inch or two of water in the pan, add 1/4 to 1/2cup of baking soda, let set for a couple of hours, then you may have to scrub or you may have to just rinse.

If the solutions above don't work, try a few inches of water and a couple of tablespoons of powdered dishwasher detergent; a gel product would probably work also. I used to sell cookware, and this was our "nuclear option." Bring the solution to a simmer, then turn it off and lit it sit for a few hours. The burned food should lift right off.