You need a webcam. It can be separate from the computer though. LSAC has a pretty extensive list of what's allowed and not allowed in. the FAQs https://www.lsac.org/update-coronavirus-and-lsat/lsat-flex.
Do you use lawhub? I can tell you the LSATFlex looks 100% the same as taking a PT on lawhub. Same screen. Same everything. It's essentially just like taking a test on Lawhub. Truly.