MicrosoftBarbieCastillo, You can already do this when the PDF is in the OneDrive/SharePoint view. It is currently a bit hard to discover as you must select the "i symbol in the top right of the PDF then select "More details" at the bottom. RickTurner, this could be made more fluid of an experience for the end user. Seems like it is still using the legacy SharePoint commenting UI vs the updated fluid framework (now present in Microsoft 365 apps).
On that note RickTurner please include Microsoft 365 SharePoint/OneDrive commenting even when in the Adobe PDF view within Edge. Currently users lose that function when opening in Adobe PDF reader for Edge.
