Open a project in the desktop app
From the web Export menu choose "Open in Eddie app" to open the same project in the desktop app; if the app is not installed you will be prompted to install it.
You can move from the web to the desktop app to get native playback and MP4 rendering on the same project.
Open it
On the web, open the Export menu.
Choose Open in Eddie app.
The desktop app opens the same project. If you don't have the app installed, you'll be prompted to install it first.
Why switch to desktop
Native playback of local footage.
MP4 rendering — see Render a finished MP4.
Good to know
Opening a project this way selects it in the desktop app for the account you're signed into there — it won't expose a project to a different account.
Related: install the desktop app, render an MP4.