You have an Azure virtual network named Vnet1 that contains a single subnet. Vnet1 and an Azure App Service app named App1 are both deployed to the West Europe region. You must give App1 access to resources in Vnet1 while keeping costs as low as possible. What should you do first?

To integrate an Azure App Service app with a virtual network using VNet Integration, the App Service app needs to be delegated to a specific subnet within that virtual network. Therefore, the first step is to create a new, empty subnet in Vnet1 that can be dedicated to the App Service VNet Integration. Creating a private link is incorrect because Private Link is used to bring Azure services into your virtual network, not to integrate an App Service with a virtual network. Creating a NAT gateway is incorrect as it's used for outbound internet connectivity with a static public IP address, not for VNet integration. Creating a gateway subnet and deploying a virtual network gateway is incorrect because this is used for VPN or ExpressRoute connections, not for direct VNet Integration of an App Service.