Editing the site text as mentioned above is the simplest way to provide some instruction, but you’re limited to text-only in that context.
If you want to add some HTML (links, images, etc) you can create a new theme component from the themes & components admin area.
From the components tab (admin/config/customize/components) you can click “install”, then “create new”, give it an obvious name… and then once your component is created, “edit code.”
From there you would go to the JS tab and can add something like this
import { apiInitializer } from "discourse/lib/api";
const CustomMessage = <template>
<div class="custom-2fa-message">
Your custom content here above the existing content.
<a href="#">Example link</a>
</div>
</template>;
export default apiInitializer("1.0", (api) => {
api.renderBeforeWrapperOutlet("user-second-factor-wrapper", CustomMessage);
});
This way you can add links or whatever HTML content you want
If you have a topic you’d like to link to here, you can make one available publicly using the Page Publishing feature: