How i can solve this error in HTML, google signin new library. Problem with signout button

I have this HTML and JS code:

<script src="https://accounts.google.com/gsi/client" async defer></script>
                            <div class="loginButton" id="loginButton">
                                <div id="g_id_onload"
                                     data-client_id="314858521059-0ss42dso5d8hn5992mjf5qkcnnhge1vq.apps.googleusercontent.com"
                                     data-callback="handleCredentialResponse" data-auto_prompt="false"></div>
                                <div class="g_id_signin" data-locale="en" data-type="standard" data-size="large"
                                     data-theme="filled_black" data-text="sign_in_with" data-shape="circle"
                                     data-onsuccess="handleCredentialResponse"></div>
                            </div>

And JS code:

function signOut() {
                var auth2 = gapi.auth2.getAuthInstabce();
                auth2.signOut().then(function(){
                    alert("Test sign out");
                    $(".g-signin2").css("display", "block");
                    $(".data").css("display", "none");
                });
            }

And in conclusion i have this problem in my console, when i want to press log out button:
Uncaught ReferenceError: gapi is not defined at signOut (about.html:225:29) at HTMLButtonElement.onclick (about.html:189:75)

Thank you in advance!

I was trying to find some resourses to solve this problem, but every time i had the same result as you can see.