Ios 15.74 not download in iphone 7

iPhone 7, iOS 14

A question: 

1.

Do you have a MDM profile?

If so, contact your company - IT department.

2.

Have you install / use iOS Beta version?, if so remove the beta profile (Settings -> General -> VPN & Device Management).

Then Restart your iPhone and check for updates again.

If neither applies, see ⤵️

You can update to iOS 15.7.6, you can check by reading this Apple article:

iPhone models compatible with iOS 12 -> iOS 16.

iPhone models compatible with iOS 15.5 – Apple Support (UK)

Go to Settings -> General -> Software Update -> Download and Install.

You need about 6 GB device storage and good Service and/or Wi-Fi.

If they are On, turn Off Hotspot & VPN.

Charge the battery > 70%.

See the following Apple articles:

Update your iPhone, iPad, or iPod touch

Update your iPhone, iPad, or iPod touch - Apple Support (IN)

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

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

You can do the update via PC, see this Apple article: Update software on iPhone, iPad or iPod touch in iTunes on PC

Update software on iPhone, iPad or iPod touch in iTunes on PC – Apple Support (UK)

If you have a Mac see this Apple article: Update your iPhone, iPad, or iPod touch with the Finder

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