New version is downloaded but can install.. what should I do

The Apple articles below may help.

Update your iPhone, iPad, or iPod touch with the Finder - Apple Support (CA)

Update your iPhone, iPad, or iPod touch with iTunes - Apple Support (CA)

gisele275 wrote:

I h as an iPhone SE, and it’s version 13.6

If you are on 13.6 you may have installed the iOS 13 beta at some time in the past. Go to Settings/General/Profiles (right below VPN), open it, tap on the beta profile and delete it, then restart your phone. If you don’t see Profiles under VPN or it doesn’t contain a beta profile that is not the issue.

Instead, to update over the air from the phone all of these requirements must be met:

• You need at least 6 GB of free storage
• You must be connected to a Wi-Fi network (and not a personal hotspot) unless it is an iPhone 12 or 13 series with an active 5G network connection
• The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
• The phone must not be in Low Power Mode
• The phone must not be connected through VPN
• The phone cannot be in Airplane mode

If you can't meet all of them you can still update using your computer.

The user tip below may offer clues.

Updating iOS: common issues and solutions - Apple Community

NOTE: You may need to update using a computer to complete the update.

Which version?

Which device?

Which version of iOS is on the device now?

Which device?