How do I download it?

Hello Ema126,

Thank you for using Apple Support Communities!

We understand from your post that you have not been able to install the iOS 14 update. Try restarting your iPhone and if necessary, remove the update and download it again.

Restart your iPhone - Apple Support

If your iPhone, iPad or iPod touch won’t update - Apple Support

"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.

Best Regards.

Turn off the Energy saving mode.
Charge your iPhone and try again.