Google has ended support of its first-gen Chromecast dongle. These alternatives are your best bet for a replacement.
Looking back at the original Google Chromecast, which just turned 10 - The Verge
Google quietly ends support for decade-old Chromecast (1.gen) : r/Chromecast
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Here's how to make your Samsung Galaxy screen mirror to Chromecast devices - PhoneArena
The first Chromecast is obsolete. Here's what you should get next
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Google Chromecast (3rd Generation) Media Streamer - Black : Electronics
Original Chromecast not receiving major updates, only fixes - 9to5Google