How to get roxygen2 to interpret backticks as code formatting?

Question

The standard way of writing documentation with code formatting is by using \code{}.

That is, #' @param foo value passed on to \code{bar()} becomes

Arguments

foo    value passed on to bar()

However, I've seen some packages (i.e. dplyr) using backticks instead of \code{} to the same effect. This is much better, since it's less clunky and allows for very nice syntax highlighting.

However, if I try that on my own package, the backticks get interpreted as... just backticks, like any other character.

The documentation for dplyr::across(), for example, starts with:

#' @description
#' `across()` makes it easy to apply the same transformation to multiple [...]

which gets compiled and displayed in the man page as:

Description

across() makes it easy to apply the same transformation to multiple [...]

But if I try something similar on my package, I get:

Description

`across()` makes it easy to apply the same transformation to multiple [...]

Weirdly, I've forked the package glue (which also manages to use backticks for code formatting) for a simple PR, and if I build the package locally, the backticks work (I get code formatting). Can't for the life of me figure out why it works there but not for my package.

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So, is there some setting I need to modify to get this to work? I checked the dplyr.Rproj but found nothing relevant. I also glanced at the Doxyfile, but didn't know what it did or what I'd even be looking for there.