Probably just upper torso stuff with weights

I broke my spine in two places recently, and can't really stand for long. So my docs had me doing some chair exercises to keep as much core strength as I can before I start physical therapy.

You'll want to ignore the first ones that require planted or moving feet and focus on the dance, core, and upper body ones

Hope you recover quickly :)

When my spouse was bed bound due to a broken ankle, they were told to do various leg raises, clamshells and dead bugs.

You might want to just rest instead of sweating in your bed.

To answer the question, stretches, crunches sit-ups twists, dumbell press if you have them, curls, laying down rows

If you have access to a sauna, there are studies associating sauna usage with decreased muscle loss in people with casts

I do these in bed, a rope-loaded kettlebell:

(with the weight hanging beside the bed, with me lying supine in bed -- holding the handle only)

However, the risk of injuring yourself or damaging furniture is 100x higher in bed compared to at a more appropriate location. There are dozens of ways to injure yourself due to unforeseen "death traps" as I call them, like getting pulled off the bed due to Newton's "equal and opposite" force-pair law for example.

I also use a "screw hook" drilled into my window sill connected to a $6 "50-pound (20kg) exercise band" from Amazon which I also connect to the handle via a carabiner so I can do lateral raises while watching Veritasium videos on my wall mounted tv that floats above the foot of my bed.

You could work on your arms?

I stretched my tendons in both my feet like 5 years ago and was mostly unable to walk without terrible pain for 2 months. After they healed for the most part doctor had me spell out the alphabet with both feet. Not sure if that helps you out or anything but it did wonders after awhile.