This is what I get when trying to import the QuickChat solution:
The solution file is invalid. The compressed file must contain the following files at its root: solution.xml, customizations.xml, and [Content_Types].xml. Customization files exported from previous versions of Microsoft Dynamics 365 are not supported.
@LycheeYum - I should specify that this is a canvas app with an embedded flow rather than a solution. Import it by going to Power Apps > Apps > Import canvas app (on top ribbon)
This is what I get when trying to import the QuickChat solution: