You need good internet connection and it takes a lot of time. In my case it tool over 2 hours.

As suggested by vinodsolanke , i updated via smart switch from pc. But this is the only area where I feel, android lacks. On iOS there is one specific date, when all users gets upate at the same time. But in Android we have ti wait.. check over and o...

Thank you vinod 

Thanks  is there any way to update manually via desktop ?

Same here . I think Samsung forgot about note 20 4g varient. All other devices started receiving update. Bot it's lonely here