How to get burn off the bottom of a pot

You've got a lot of options. My favorite is baking soda and vinegar and then scrub with a ScotchBrite pad. (The baking soda and vinegar reaction takes me back to science class and making volcanoes.) If that doesn't do it, then a Brillo pad to the rescue. But there are more ideas https://jezebel.com/how-to-clean-scorched-pots-and-befouled-ovens-1443087464

depends on what pot it is ?However Bar keepers friend may be of help

When I scorch food, I pour white vinegar to cover, let sit for a day or two, and use a flat wooden spoon to scrub it out. I have even used the top rim of a kitchen sink strainer to scrub, which is highly effective.

Sand will take it off. Use a grub and scrub the bottom with sand and water

Try submerging the pot in water and throw in a dryer sheet and some Dawn dish detergent. Soak overnight. It should come off fairly easily.

Salt and vinegar.. Baking soda scrub with it paste like

Barkeepers friend works great