works in Chrome but error in Safari browser

I'm making a website and the 'sign up' function works well in Chrome but not in Safari.
The error I got from Safari:

Request method 'POST' not supported

Here is my Controller:

@ResponseBody
@RequestMapping(value = "/signUp", method = {RequestMethod.GET, RequestMethod.POST} , produces = "text/plain; charset=UTF-8")
public String signUp(User user) throws Exception {
    System.out.println(user);
    boolean newUser = userService.insertUser(user);
    
    if (newUser) {
        newUser = true;      
    } else {
        newUser = false;
    }
    System.out.println(newUser);
    
    return newUser + "";
}

js:

$("#kt_login_signup_form_submit_button").click(function() {
    var userArray = $('#kt_login_signup_form').serialize();
    console.log("# ---" + userArray);
    $.ajax({
        url : 'signUp',
        data : userArray,
        method : 'POST',
        dataType : 'text',
        success : function(textData) {
            console.log(textData);
            if (textData.trim() == "true") {
                kt_login_signup_form.name.value = textData.name;
                kt_login_signup_form.phone.value = textData.phone;
                kt_login_signup_form.id.value = textData.id;
                kt_login_signup_form.pw.value = textData.pw;
                kt_login_signup_form.pw2.value = textData.pw2;
                kt_login_signup_form.email.value = textData.email;
                kt_login_signup_form.bod.value = textData.bod;
                kt_login_signup_form.gender.value = textData.gender;            
            } 
        }
    });
});

JSP form tag:

<form class="form" id="kt_login_signup_form" method="post">
    ...
</form>