Why I can’t find WhatsApp on my iPhone AppStore

iPhone 6s Plus, iOS 11

If you indeed have an iPhone 6S Plus and that iPhone is still running iOS 11, then you need to update your iPhone first.

Check iPhone type & iOS version -> Go to: Settings -> General -> About.

If it is an iPhone 6 or 6 Plus you can update to iOS 12.5.6.

If it is an iPhone 6s or 6s Plus you can update to iOS 15.7. 

You can check here -> iPhone models compatible with iOS 16

iPhone models compatible with iOS 16 – Apple Support (UK)

Then go to Settings -> General -> Software Update -> Download and Install.

You need about 6 GB device storage and good Service & 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

The reason why you should update first, because the most apps require iOS 12 or later.

WhatsApp requires iOS 12.0 or later.

YouTube requires iOS 12.0 or later.

Facebook requires iOS 13.4 or later.

I can’t find apps like YouTube, Facebook, and WhatsApp on my iPhone AppStore

Do you get any error message when you search for those apps?