https://wccftech.com/gmail-is-now-sending-chat-integration-feature-to-personal-google-accounts/

Google rolled out the Google Meet, Chat, and Rooms tabs in Gmail last year, but at that time, the feature was exclusive to G Suite users only. The feature brought new tabs to the Gmail interface, making it easier for users to stay in touch with everyone and collaborate on work. The feature is finally rolling out to personal accounts and allowing all the users to access the new Chat and Rooms tabs.

The feature is now available to enable the new Chat integration; you can look at the screenshots below and find the new Chat option in the app settings to enable you to enable the Chat and Roobs taps. To enable this feature, you have to tap on the checkbox next to it and then tap on "Try It" in the following pop-up.