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Integrating AVD Remote Apps with locally installed apps is not natively supported. Users will need to save the PDF to a shared location accessible by both local and remote applications. https://learn.microsoft.com/en-us/mem/intune/fundamentals/azure-virtual-desktop
To RemoteApps available in AVD, you need to publish them by adding them to an application group, which is then linked to a host pool and workspace, users to access these applications as if they were installed locally.
Please find the below document links for your reference:
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