i have imac 2017 running boot camp the sound only work with windows

As its fine on the windows OS, I would suggest testing in different user account on the Mac, if you dont have one it takes 2 mins to set up : https://support.apple.com/en-ie/guide/mac-help/mtusr001/mac

This would help isolate the issue further

As a more advanced step you could also after test in new user boot it into safe mode, this stops 3rd party extensions from loading in Mac that could cause this issue:https://support.apple.com/en-ie/guide/mac-help/mh21245/mac

On an intel Mac just hold down the SHIFT key on the start up chime

Check About This Mac -> System Report -> Audio. Do you see any of the internal devices? If yes, check if your sound is muted? If it is not muted, disconnect teh USB sound card run a SMC Reset - How to reset the SMC of your Mac - Apple Support and test.

Hi

Its hard to help with this information

Is this just effecting internal sounds, wire headphones, wireless headphones?

Are multiple apps effected? like music and FaceTime?

Do you have any external displays connected?

check in system preferences > sound and send a screenshot of output menu