WhatsApp and Facebook not working on my iPhone 6 Plus

If you still have the iPhone 6 Plus listed in your profile, unfortunately it cannot run the newer and more demanding iOS versions that WhatsApp and Facebook require.

Bottom line.....you need a new phone......an iPhone 8 at minimum. An iPhone 11 or higher would be recommended.

whatsapp should work on your iphone 6 plus as it requires ios 12.0 or later… but facebook requires ios 13.4, so you’re going to have to upgrade your phone.

Contact Facebook and WhatsApp for issues with their website, app or service

Please read my reply again. You need a new phone.

How can I upgrade iOS

You can't, if you have an iPhone 6 or iPhone 6 Plus that is running iOS 12.5.7

That is the end of the update road.

Why is WhatsApp and Facebook not working on iPhone 6plus