Cannot install after downloading

Hello jc0106.

Thanks for reaching out to Apple Support Communities. We see that you are having some trouble with installing the iOS update for your iPhone. We will be glad to assist. Try the steps below from the following resource: If your iPhone, iPad or iPod touch won’t update

"Remove and download the update again

If you still can't install the latest version of iOS or iPadOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.
2. Find the update in the list of apps.
3. Tap the update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest update.

If you don’t see the update in the list of apps or if the issue happens again, you need to update your device with your computer using Finder or iTunes."

Cheers.