Hi @BRS ,
Do you mean you want to use Office for Mac with Product key but not office 365 subscription plan for Mac?
If yes, please refer to this support article:
https://support.microsoft.com/en-us/office/using-product-keys-with-office-12a5763a-d45c-4685-8c95-a44500213759
If my understanding is incorrect, please provide more information about your problem and I'm glad to help you.
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