gender mandatory

frontend/src/Register.tsx

@@ -179,14 +179,13 @@ export const Register = () => {
             </div>
             <hr />
             <div className="field">
-              <label className="label">
+              <label className="label">gender</label>
-                gender <small>(optional)</small>
-              </label>
               <div className="control">
                 <div className="select">
                   <select
                     name="gender"
                     value={gender}
+                    required
                     onChange={(e) => {
                       setGender(e.target.value as Gender);
                       setError("");