Call waiting not working

[RAJ1407]

Hi, Good Morning

I tried all Keys *43# And Onece I Press  #43#  for Deactivate Then again  I Again Press *43# But It's not working Also I tried My Phone I swich Off And On It But Not Solve It 

Now What I do Can U Plez Guide Me I am Using Iphone 11 Pro Max .

Thanks 

[BandOfBrothers]

Not sure if this will help @RAJ1407 

https://deviceguides.vodafone.co.uk/apple/iphone-11-ios-13-1/calls-and-contacts/turn-call-waiting-on... 

🌈 Stay Safe & Stay Alert.  🌈