What is the proper way to respond if someone thanks us by saying 'Jazakallah Khair'?

**What is the proper way to respond if someone thanks us by saying 'Jazakallah Khair'?** Do I say > wa ʾiyyākum (وَإِيَّاكُمْ‎) or do I say > "wa ʾantum fa-jazākumu-llāhu khayran" (وَأَنْتُمْ فَجَزَاكُمُ ٱللَّٰهُ > خَيْرًا‎) ***Or is there a third more preferred way (as per Sahih Hadiths)?***