If you are asking how to convert an evaluation version of Windows Server 2022 to a production version, please refer to https://docs.microsoft.com/en-us/windows-server/get-started/upgrade-conversion-options. If you are asking about the expiration of the current VNext Insider builds, we will publish newer builds with a later expiration date before the current date expires, and a simple build-to-build upgrade will then extend the expiration date for you.
22538 is not an Evaluation version of Windows Server 2022. 22538 is a preview version of Windows Server VNext (the branding in the preview has not been updated yet). Evaluation version of Windows Server 2022 may be obtained here: https://www.microsoft.com/en-us/evalcenter/evaluate-windows-server-2022. The Evaluation edition may be converted to production with the appropriate product key. Hope this helps.