Pass encrypted Key special characters with by URL to consteller

Question

I use the following link which contains an encrypted key to call my controller:

http://localhost:48754/home/index2?Key=yU/iMD+TJtNIsJYasLf/pfSmH+tPvIOhKMuw45Fw0OwsoVrMFqqq+HLDgiJZKfGkP0OxZk1GhE/iVw8EVSQ9vg==

my controller is :

public ActionResult Index2(String Key)
        {

          
            Client Cl=new Client();

            var keyDcrypte = "b14ca5898a4e4133bbce2ea2315a1916";
            //var keyDcrypte = "ES0FT678LDPSC45";
            var str = Key;

            var decryptedString = AesOperation.DecryptString(keyDcrypte, Key);
            var usernamePasswordArray = decryptedString.Split(',');

            Cl.Name = usernamePasswordArray[0];
            Cl.Province = usernamePasswordArray[1];
            Cl.Email = usernamePasswordArray[2];
            Cl.Tel  = usernamePasswordArray[3];
          
            return View(Cl);
        }

my problem is instead of having the parameter key passed to url which is : yU/iMD+TJtNIsJYasLf/pfSmH+tPvIOhKMuw45Fw0OwsoVrMFqqq+HLDgiJZKfGkP0OxZk1GhE/iVw8EVSQ9vg==

I receive the same value but without the + : yU/iMD TJtNIsJYasLf/pfSmH tPvIOhKMuw45Fw0OwsoVrMFqqq HLDgiJZKfGkP0OxZk1GhE/iVw8EVSQ9vg==

do you have any idea how i can always have the same parameter passed in url et thanks for the help !!!