Create a component under the username in posts

[david (David Taylor)]

@SubStrider

This is part of the core now, right?

As long as all your other themes/plugins are updated, then yes Details here:

Upcoming post stream changes - How to prepare themes and plugins

We’re moving away from the legacy “widget” rendering system, replacing it with modern Glimmer components. We’ve recently modernized the post stream using Glimmer components. This guide will walk you through migrating your plugins and themes from the old widget-based system to the new Glimmer implementation. Don’t worry—this migration is more straightforward than it might seem at first glance. We’ve designed the new system to be more intuitive and powerful than the old widget system, and this g…