Hi @Ron Simon
Based on our research, Adobe Acrobat for Microsoft Teams provides an integrated bundle of PDF services, enabling you to perform various operations on your PDFs and collaborate with other team members in real-time. To use this app, you need to install it and set it as the default PDF viewer in Teams. Otherwise, Adobe Acrobat as a default PDF viewer in Teams works only on desktop and web clients. It isn’t supported on the mobile client.
To set up the app as a default PDF viewer, allow third-party apps in your tenant and then you may refer to the article.
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