you are passing a single string variable to a dictionary of key (string type) value (string type) pairs
change the type of in_columnname to string in your variables list
plz give example
just change in_columnname variable type to string - why would you need an example?
becoz i already done this, but its not working
please provide the screenshot which shows you have done this, where type is now string.
then provide the exact error you are receiving.