I am trying to update software for this device but not update

What happens when you go to Settings -> General -> Software Update?

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)

Optimize the range of the mobile network (service)

You need good Wi-Fi.

If they are On, turn Off Hotspot & VPN.