Creating an integration for both Regular and Business users

JimmyMcnulty To confirm, Здравко is correct; you can and should use the same user scopes on a single app with the same files endpoints to work with files in both business and non-business accounts. You don't need team scopes to work with files in accounts that happen to be on business teams. For example, to upload files, you would use the same /2/files/upload endpoint which only requires the "files.content.write" user scope, whether or not the user is a on a team. (You would only need team scopes to perform operations on the team, such as to add/remove team members.)

One difference though is that by default, API calls to the Dropbox API operate in the "member folder" of the connected account, not the "team space". That means that by default, the contents of the team space will not be found and uploads will go to the member folder, not the team space. You can configure API calls to operate in the "team space" instead though, in order to interact with files/folders in the team space. To do so, you'll need to set the "Dropbox-API-Path-Root" header, but you can still do so without team scopes. You can find information on how to use this in the Team Files Guide.