How do I update my Apple TV to tvOS 18.2 for Amazon Prime Video app?

I have a popup stating my Amazon Prime Video will require me to have TVOS18.2. I am currenty on 18.1 and the update fails. My A1842 21GB is currently on 18.1 [22J580]. There is no facility to let you know how much free space I have, but I do not have many apps.

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