How can I automatically install from CodeCommit onto a Raspberry Pi

I want to be able to use CodeCommit as a repo for my scripts, and then have AWS automatically deploy any new commits to a bunch of Raspberry Pi systems (on-premise instances which I've already set up in Systems Manager). Preferably, it would take a commit and install it on a single staging RPi first, test it, and if the tests go well, then install it on the rest of the fleet of RPi systems.

(The Raspberry Pi systems are running Ubuntu Server 20.04 LTS, so are all compatible as per the requirements of Systems Manager)

I've spent all week reading the documentation and going through the tutorials for CodeCommit, CodeDeploy, CodePipeline, and Systems Manager... and I'm getting nowhere.

Is this even possible with AWS? Are there any clear guides on how to do this?

The closest I've come to success was following this: https://docs.aws.amazon.com/codepipeline/latest/userguide/tutorials-simple-codecommit.html, but that tutorial explains how to deploy from CodeCommit to an EC2 instance rather than to an on-premises instance. I tried switching to an on-premise instance instead of EC2 (in step 5), and specified the tags I've already assigned to my on-premises instance (in Systems Manager > Fleet Manager), but when I try to run the deployment, I get an error: "The deployment failed because no instances were found for your deployment group. Check your deployment group settings to make sure the tags for your Amazon EC2 instances or Auto Scaling groups correctly identify the instances you want to deploy to, and then try again." The tags are definitely correct. I have no idea how to fix this.

Thanks in advance for any help.
Dave