Sync phone contacts to Whatsapp

Do the below simple procedures....

System Settings
then, Security and Privacy
then, Application Permissions
then, WhatsApp
Turn Location: ON
Contacts : ON
Email & PIN Messages: ON
Shared Files: ON
Text Messages: ON
Device Identifying : ON
Microphone: ON
Then go back into Whatsapp, refresh contacts and Give it 24 hours and all your contacts will appear. Switching WIFI ON can speed up the process.