On the desktop or laptop, does Video Screenshots appear in Zwift settings? If not then your CPU can’t handle the feature. If it’s there and enabled then you should be able to access it via the in-game action bar.
If your PC and laptop are running Windows, you should check if you have one of the processors listed in this post:
Also be aware that (especially on Windows) there can be a significant performance loss by enabling the feature, depending on how strong the CPU is.