Hi @tarment, welcome to the forum!
Please take a look at the “how to” for some tips to improving your question:
This is easily found no matter where you are on the forum - there’s a FAQ link on the left of every page - even this one!
A few things that stand out to me are:
- The title of this post should be a question
- Properly formatting code. You are providing specific code examples and that is great. But if you look at your post the formatting has gotten screwed up. This is because the
#character is used by the forum to indicate a tag, like Questions . To avoid that use the back tick character (`). More details about this are given in the link above
As for the question itself. The following code produces the screenshot below.
#table(
columns: 3,
table.header($n_("old")$, strong($n_("old")$), math.bold($n_("old")$)),
[A], [B], [C]
)

Is this enough information to apply to your specific use case? If not please post a complete minimal working example of your code that isn’t working. See here for why this is so helpful when seeking answers online. It really helps us to help you.