Hard to tell the space available, but could you sister in another piece of wood that runs along the backside of that one to brace it from behind? Or use a u shaped metal cuff (wrong term probably) to secure the two cracked ends together? Either way, I think adding an extra leg support (again probably the wrong term) to each side for additional support of that expanse. Or does the bed disassemble enough that you could remove that piece and have a new one cut and stained to sort of match. But all that said, my first call would be to pottery barn just to see if they happen to have a suggestion or a phone number of the factory that made it, or a local store/shipping warehouse (they have one near me and have big sales to clear out the damaged items, returns, overstocked items). And it couldn’t hurt to scan Craigslist or FB to find one for sale you could use for parts.

donald i will take a better picture with the mattress and boxspring off the bed to see the real damage after my husband gets home from work. unfor unfortunately this happened at 1 am last night when i got up to use the bathroom so he was too tired to take everything off the bed and just went under the bed to take the picture. the part that sucks is the one rhat broke is attached to the upholstured side part going long ways on the bed so im hoping somerhing can be done 🤞🤞🤞

Call them!

Hu- just did and all they said and did was give me the name of a furniture repair webaite called furnituremedic.com. they have horrible customer service.