Try reading the documentation on the .Add method of the parameters collection.
https://docs.microsoft.com/en-us/dot...tframework-4.8

There's two overloads that has two parameters... and both expect something that can be converted to integers in that second parameter. You didn't supply something that could be converted to an integer. You supplied a string. As Yosemite Sam would say "No that's not right, try it again!"

-tg