When you create items based upon a Page Design, you can connect to your Dropbox account through the Sync menu. This will prevent the need to login to your account every time you want to create a new Page design.
To connect to Dropbox
Select Integrations from the User menu at the lower left side:
2. Press Connect to connect to your Dropbox account:
3. Enter your Dropbox login credentials or click Sign in with Google to use your Google credentials.
Note: You will be prompted by Google to allow Craft to view the files, and metadata in your files, stored on your Dropbox account.
3. Click Allow to provide Craft with access to your files and folders on Dropbox.
The Tools panel will show that you are connected to your Dropbox account.