Hey Siri isn’t with WhatsApp on my iPhone to send messages

Hi

To fix the problem, you have to: 

Open WhatsApp app on your iPhone > Settings > Privacy > Screen Lock > “Require Face ID” / “Require Touch ID”. Disable it.

I had the same problem. It works with me.

I hope it’s helpful.

You will need to contact WhatsApp for help with their software, this is not an Apple product.

Here is a link to their help page.

https://www.whatsapp.com/contact/?subject=messenger