Hello Dinusha,
If it is a eval licenses, it would not impact much, as Eval is also 90 days and the server will also work for 90 days without activating. only if it is a permanent license, if you don't activate within 90 days, you wont be able to use the feature.
To answer your question, if you do not activate a eval license, it will still work and will give you the same access.
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