Each Mixpanel account can contain multiple projects. Each project has its own unique routing number, which we call a project token. Whenever you want to send data to a specific project, you'll need to specify the project token so we know where to put the data.
Locate Current Project Token
Click the Settings gear in the upper right hand corner of your Mixpanel project and select Project settings to see your project token for only the project you’re currently viewing:
All management options and project access keys are available in the main Overview tab.
Locate Tokens for All Projects in Your Mixpanel Account
To view the project tokens for all your projects, click the Settings gear in the top right of Mixpanel and select Personal Settings.
Then select the Projects tab.