added zod for post requests

hooks/store/tokens.tsx

@@ -27,6 +27,9 @@ const useAddToken = () => {
       const response = await fetch("/api/v1/tokens", {
         body: JSON.stringify(body),
         method: "POST",
+        headers: {
+          "Content-Type": "application/json",
+        },
       });
 
       const data = await response.json();