x-csrf-token value in Odata Service PUT operation

Hello Experts,

I have created an Odata Service for flight demo.

I have successfully implemented the GET_ENTITY & GET_ENTITYSET methods and tested them.

Now i am trying to implement the CREATE_ENTITY method. Data and Model both classes are up to date.

Now I am trying to call the PUT method of REST in Mozilla Firefox for testing purpose.

I have installed the REST CLIENT Add-on for Firefox.

After clicking the Send button i am getting the below error.

"CSRF token validation failed"

The cause of this error is i have supplied wrong value for x-csrf-token.

My Question is from where can i get the value of x-csrf-token when i am calling an Odata service for testing purpose from a browser with rest client add-on installed?