Family plans are currently not available in Belarus, Iceland, Israel, Slovenia, South Korea, or Venezuela. Our teams are working to expand Family Plans in other markets in the future, however we have no concrete dates at this point.
Even though this specific feature isn’t currently available, thanks for letting us know that it’s something you’d like to see! We use the Send Feedback tool to track all requests: https://yt.be/help/feedback. Drop it there so the right team sees your comments.