New th in topic table

You need to have some prior knowledge of handlebars. Then, go through the source code of discourse and find the corresponding path.

https://github.com/discourse/discourse/blob/main/app/assets/javascripts/discourse/app/raw-templates/topic-list-header.hbr

Then create a new file with the same name in your theme component according to the path to overwrite it, just like the example below

https://github.com/discourse/discourse-mobile-op-avatar-component/blob/main/javascripts/discourse/templates/mobile/list/topic-list-item.hbr