Try variety in color for the diet. My tortoise refuses to eat orange carrots but eats all the other colors of carrot. If you can’t get him to eat in the next week I would take him to get checked for parasites to be on the safe side. You could also try enticing him to eat with a tiny amount of...
Maybe try feeding veggies that are really watery. Cucumber doesn’t have much nutritional value but it does have a lot of water in it which can help hydrate. Some cacti might also help.
Orchid bark is good just don’t get large chunks or they might try to eat it. You can also try to mix it with coconut fiber to help retain even more humidity as well as some moss.