Create a Bitrise App connecting your repository to Bitrise.

The Bitrise Project Scanner will configure your project for you and start a build. The first build will fail until we have configured the TheAppsPajamas Service Account Key.

Bitrise Workflow Xamarin Easy Sample App Configuration

Add TheAppsPajamas Service Account Key Installer to your workflow.

Bitrise add TheAppsPajamas Service Account Key Installed Step

You can install TheAppsPajamas Service Account Key Install Step anywhere in your Workflow, as long as it appears before the Xamarin Archive Step.

Select the TheAppsPajamas Service Account Key Installer Step, and choose Select secret variable 
Bitrise Select Secret Variable
Create a new Secret Variable to store your Service Account Key in. These Secret variables are not exposed by Bitrise.
Bitrise Create New Secret Variable

After you've created your Secret variable you're ready to Start a Bitrise Build!

Bitrise Secret Variable Selected