You can’t see React tab because, Facebook have updated React DevTools to have Components and Profiler Tabs. ⚛️ Components tab serves same purpose as React tab in older versions. From description,
You will get two new tabs in your Chrome DevTools: “⚛️ Components” and
“⚛️ Profiler”.The Components tab shows you the root React components that were
rendered on the page, as well as the subcomponents that they ended up
rendering.
This can be seen from version 4.0.0. See the release notes here