SPSS MacOS Licensing
Navigate to your "Applications" folder in "Finder" by clicking on the desktop, and pressing keys Command + N.

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Navigate to directory "IBM/SPSS/Statistics/26" (the example below is for SPSS ver 26, in your case might be 27, 28, or, newer) and double click file "SPSS Statistics License Authorization Wizard" to start the licensing wizard.
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Click "Next".
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Check radio button "Autorized user license ..." followed by "Next".
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Enter the license code from your email followed by "Add" and "Next".
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On the next page you'll see the button "Finish". That completes the installation.