Failing to retrieve backpack on BAZAAR.TF

[no commander]

I don't know if this is the right place to post this, but whenever I try to open a new trade on BAZAAR.TF, it won't load my TF2 backpack; it says there's an error or it even says my backpack is empty oO, any help?

I asked for help at BAZAAR.TF, but I was told this has to do with STEAM and not them, hence they can't help me.

[nullable]

Well your inventory on Steam is the source of truth. There's a couple of reasons why the website can't get data back from the Steam api. It could be the website's issue. Or there could be some outage on Steam's side. If it's the former you have to wait on the website to figure out it's something the can manage. If it's the latter you have to wait for Steam to recover. Not much you can do but wait in either case.