It’s not letting me download Roblox back

Hi niyah205,

Thank you for posting in the Apple Support Community. In order to download an app that you previously had installed on your iPad, follow the steps below from the article Redownload apps and games from Apple:

1. "Open the App Store app.
2. Tap the sign-in button  or your photo at the top of the screen.
3. Tap Purchased.
4. If you use Family Sharing, tap My Purchases or choose a family member’s name to see content that they purchased.
5. Tap "Not on this [device]."
6. Find the app that you want to download, then tap the download button ."

This will allow you to locate previously downloaded apps from your account and reinstall them back to your device. If you run into any trouble installing the app with those steps, this article provides additional guidance: If there's an issue when you redownload apps, movies, or other content from Apple.

Hope that helps!