my mac has os x el capitan version 10.11.6 and I can't seem to update. there is no update available in app store.
how do I update to newer software version.
iMac 21.5″, OS X 10.11
Back up your data, check your applications for compatibility, and depending on which Mac model you have, click on High Sierra, Mojave, Catalina, or Big Sur. They're full-version upgrades and won't appear in the Updates list.
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