I am facing a situation where I have to add a custom lookup field Document Type or Category into system forms of Upload and Edit Properties Sharepoint Document. Purpose of this is to categorize and identify a document such as whether its Passport, Degree Certificate, Photo, Birth Certificate etc.
In on-premises Dynamics 365 we can modify FormJson and FormXml in SystemBaseForm entity whereas in online Dynamics 365 this entity SystemForm is not modifiable as per my experience. I tried to update FormJson and FormXml using SQL 4 CDS and WebAPI as well but it didn't update.