I didn't have this exact problem tonight, but a similar one. I think it's an instructive hand in making sure you make your contract.
You are declaring 3NT and are grateful to get a spade lead. You beat the K with your ace and lay down the ♦J. LHO plays the K. Over to you.
T1: ♠2 - 4 - K - A
T2: ♦J - K - ?
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3♦ - 3NT
All Pass