DeepRacer boot error

I performed the environment setup for https://github.com/aws-deepracer/aws-deepracer-launcher/blob/main/getting-started.md and rebooted, but the DeepRacer's battery LED remains yellow, not changing to blue. I attempted https://docs.aws.amazon.com/deepracer/latest/developerguide/deepracer-ubuntu-update.html, but the following screen appears, and the process doesn't seem to proceed.

Despite trying https://repost.aws/questions/QUX4ZvFGsBSqK0wFWFUA-KIw/deepracer-boot-error#AN50Q7EU-QQkeyy3aBbxulSg, the issue persists. Please help me.