Message error: The argument type 'String?' can't be assigned to the parameter type 'String'

How to fix this? The argument type ‘String?’ can’t be assigned to the parameter type ‘String’.

>Solution :

you just need to add ! at the end of each one of your variables, so Uri.base.queryPrameters['token'] becomes Uri.base.queryPrameters['token']!
of course this is assuming that your data is not null, otherwise it would give you a runtime error.