Managed MetaData and Document Libraris

Hello, we are currently going through the process of setting up managed metadata tags on our SharePoint Online systems. The requirement has been identified that any documents need to be tagged with some labels, and I would like to make it so that, when the user creates or uploads a document to the libraries in question, that there be a popup window or some other form of forced interaction for the user that will require them to set the tags that we are wanting to use. Any thoughts would be greatly appreciated, cheers.