Welcome to the community, @AaryaYerramsett!
This child account appears to have YouTube blocked, which results in any videos hosted on YouTube not playing. The 100 Days of Code videos are hosted on YouTube, therefore not allowing you to play them.
This Ramki - Aarya’s dad. We blocked Youtube because Aarya is only 7 years old. And the video cannot be found in youtubekids. Is there a way to enable the videos in Youtubekids? Thank you so much!