Sit Anywhere by Qwazor

This is a simple datapack that allows you to turn anything into a chair. Full survival compatible -- no commands required.

To place a seat, place an armour stand named "Seat" on the block you want to sit on.

To remove a seat, punch it while holding a "Seat" armour stand, or place an armour stand named "Clear Seat" next to it

"/trigger seats_help" will print this in chat: As a server operator you can click on the red and green text to place and remove seats