So, long story short, you will need to refactor your code in order to use v3.
Here are some simple picker client examples that show what the code might look like when translated from v2 to v3. For more information about the pick method and its parameters consult the v3 pick page
Symbolic links can only be generated when selecting files from online sources. In V3 you have to specify that these are the types of links that you want to generate by using the
preferLinkOverStore parameter. If this parameter is set to true and you select a file from your desktop or mobile device, then the file is being stored and is not a symbolic link.
Have users upload a maximum of 3 Image Files. Users can choose to upload less than 3 files.
The V3 picker is able to accept a mix of mimetypes and extensions. This is not possible in V2
While this functionality is available in both V2 and V3. V3 has an
onFileSelected callback that V2 does not. With it you can contruct your own logic and even customize your own errors.
onFileSelected can be used for much more than just enforcing certain file sizes. For an example of the ways
onFileSelected can be used see the v3 recipes page.