I primarily use Nearpod which is very similar to Peardeck. I tried to add an assignment using Nearpod’s “Web Content” but it created a link to that assignment which then opened in another tab. Using the embed code was not an option for Nearpod. I am not familiar with a way to embed a Code.org project or webpage into one of these tools. Personally, I use screenshots from the assignments and projects when I am referring to them in Nearpod. Nearpod does have the option to add a video. I could do a screen recording (Screencastify or Loom) of a Code.org assignment, especially if I wanted to emphasize the animation or something similar, and that should play within the tool. I have not done that but theoretically, it should work.
Perhaps others will have suggestions or workarounds as well.