postcode different shipping

I have used the plugin flexible shipping: for example I need to create 2 methods of shipping for Spain (1 for Canarie and the other for the rest of the Spain). I have then created on method of shipping for Spain with flexible shipping where I have specified the weights and the cost without specifying postcodes and another method of shipping where I have indcated Spain (because Canarie doesn’t appear in the list of destinations) and I have specified the zip codes in the form. https://prntscr.com/lpqbr5???? https://prntscr.com/lpqc0g The problem is when I have to do check out in the cart to purchase something and I insert in my address one destination of Canarie, it doesn’t calculate it but it brings the settings of general Spain.
Furthermore, if I specify the State Spain and I put one postcode of Italy for example, it doesn’t recognised it as an error. Is it possible to do a check for it? I hope you can? help e because I don’t have other solutions.