We need to embed an app within smartbuilder.
This is the link of the game. https://lighthearted-baklava-cbc5d5.netlify.app/
How do I ensure this is not opened as a separate tab but opened within SMB itself so the user is not directed to another tab or page.

When I try the link you gave it says 'Site Not Found'.... But to embed web based content in a lesson I would use the Web Object. With this object you can point to a URL, use embed code, or point to a specific file. Without a link that works I cannot verrify if your app could be embedded.

https://healthyfood.paratus.co/

Please try this link

Yes that link works. Same advice as before. Use the 'Web Object' and in it's 'URL' property paste that link. Seems to work fine for me.