Hi @JohnI-2021 ,
you need to peer the 2 vnets:
https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-peering-overview
https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-peering-gateway-transit
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(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten