How can I see my whatsapp notifications on my lock screen? I am not getting pop up notifications when my screen is locked even though I chose the always show pop up option. How do I fix this
You can use the DashClock Widget and the DashClock WhatsApp Extension from Google Play and place the widget on your lock screen.

DashClock Widget: https://play.google.com/store/apps/details?id=net.nurik.roman.dashclock

WhatsApp Extension: https://play.google.com/store/apps/details?id=com.stallware.dashclock.whatsapp