There is a simple way like: button has class: sign-up-button
When clicked will open the registered Popup. Instead of using a: href is a signup
I used api.decorateWidget ('post: after', helper
But there is NAME:LOCATION is unique to insert a code snippet at the end of the article.
Or place to find the NAME: LOCATION
post:after should work if you want to add new elements to the bottom of a post. Note that you have a space between post: and after.
I think this is related to what you’re trying to do.
If you still have problems, then please post the rest of the code you’re using.
Thanks for your help (especially for newbies)
This is the entire code
<script type="text/discourse-plugin" version="0.8.25">
const user = api.getCurrentUser();
if (!user) {
api.decorateWidget('post:after', helper => {
let h = helper.h, attrs = helper.attrs;
// console.log(attrs);
return helper.h('div.fixed-bottom-bar.d-none.d-lg-block',
[
helper.h('div.wrapper',
[
helper.h('div.logo',
helper.h('img', {
src: 'https://thuvienmuasam.com/uploads/default/original/1X/776142524c0d5c0430a603fde63a8bad2f77b267.svg',
alt: 'ThuVienMuaSam'
})
),
helper.h('div.content.d-flex.justify-content-between.ml-1',
[
helper.h('div.float-left',
[
helper.h('span.title','Chào mừng đến với Thư Viện Mua Sắm!'),
helper.h('br'),
helper.h('span.text',
[
helper.h('span','Bắt đầu '),
helper.h('a.text-primary.cursor-pointer.sign-up-button',{ href: '/signup'},
helper.h('strong','đăng ký tài khoản TVMS')
),
helper.h('span',' để có được nhiều bài viết thú vị hơn từ '),
helper.h('a',{ href: '/u/'+helper.attrs.username },
helper.h('strong',""+helper.attrs.username),
),
])
]),
helper.h('div.float-right.d-flex.align-items-center',
helper.h('button.btn-primary.btn',{type:'button'},
helper.h('a', { href: '/signup'},
helper.h('span.d-button-label','Tham Gia')
),
)
),
]
),
]
)
]
);
});
}
</script>
I used helper.h(‘a’, { href: ‘/signup’} But when clicking the button, the page will reload instead of displaying the Registration Frame immediately
Thanks for sharing your code 
If you want the login / sign up modals to show up directly, then you need to use the built-in showLogin and showCreateAccont actions.
So instead of this
helper.h(
"button.btn-primary.btn",
{ type: "button" },
helper.h(
"a",
{ href: "/signup" },
helper.h("span.d-button-label", "Tham Gia")
)
)
you should use something like this for the signup modal
helper.attach("button", {
label: "sign_up",
className: "btn-primary btn-small sign-up-button",
action: "showCreateAccount"
})
or this if you want the login modal
helper.attach("button", {
label: "log_in",
className: "btn-primary btn-small login-button",
action: "showLogin",
icon: "user"
})
I should also note that I think adding a banner - for anon users - below every post with the signup / login buttons is very user-hostile and I would recommend against doing that. However, I don’t know much about your use-case here. Have you considered adding the banner / image at the top of your site instead of adding it to every post?
Thank you for coming back and solving all the questions 
I want to improve new users now, so I need action.
Currently only works on PC.
I am browsing through articles about cookies to be able to hide or hide when users click on hide it
أين أضع هذا الكود في ثيم النعناع الخاص بي؟
يمكنك إنشاء مكون سمة جديد وإرفاقه بسمتك.
انتقل إلى المسؤول → تخصيص
انقر فوق الزر تثبيت
ثم قم بإرفاقه بسمتك وانقر فوق الزر تحرير CSS/HTML
تضيف الكود في قسم الرأس:
آمل أن يساعد ذلك. 
في سمة النعناع، أين يجب وضع هذا الرمز؟
هل جربت الخطوات التي قدمها @Arkshine؟
نظرًا لأنه لا يمكنك تعديل السمات البعيدة، فمن الأفضل إنشاء مكون سمة خاص بك وإضافته إلى سمة mint.
console.error("API أو دالة showLogin غير متاحة.");
لقد اتبعت الخطوات ولكن عندما وصلت إلى صفحة تسجيل الدخول، لم يتم فتح النموذج تلقائيًا
<script type="text/discourse-plugin" version="0.8.25">
// Function to check if the current page is the login page
function isLoginPage() {
return window.location.pathname === "/login";
}
// Trigger login action when the page loads
document.addEventListener("DOMContentLoaded", function() {
console.log("DOMContentLoaded event fired.");
// Check if the current page is the login page
if (isLoginPage()) {
console.log("Current page is the login page.");
// Trigger login action
if (typeof api !== "undefined" && typeof api.showLogin === "function") {
console.log("API and showLogin function are available.");
api.showLogin();
} else {
console.error("API or showLogin function are not available.");
}
} else {
console.log("Current page is not the login page.");
}
// Get the login button element
const loginButton = document.getElementById("loginButton");
// Trigger a click event on the login button to open the login modal
if (loginButton) {
loginButton.click();
}
});
</script>
أتلقى console.error("API or showLogin function are not available.