This might help you It looks like the problem is with your project references. Please have a look at your project references for Flurl.dll. If you can't see Flurl there then please apply following command in your package manager window:
Do you prefer to wrap JSON arrays in another JSON object or always require POST to prevent JSON Hijacking?
By : CharCar
Date : March 29 2020, 07:55 AM
I wish this helpful for you I recently started looking into building web applications using .NET MVC and I stumbled upon this blog post by Phil Haack: JSON Hijacking. For those of you who aren't aware of this vulnerability when using JSON to transfer sensitive data it's really a must read. , I personally wrap all my responses in a comment: