http flutter post error type 'double' is not a subtype of type 'String' in type cast code example
Example: type 'double' is not a subtype of type 'String' of 'function result' dart
This will fix the error type 'int' is not a subtype of type 'double'
To fix type 'double' is not a subtype of type 'String', you need to find out
the parameter which is returned as a double and you are trying to initialize
it to a string variable.