Signature help?

[KillTheMule]

I've just started using typst-lsp with neovim, and I've basically got it working (I do get completion, which is very helpfull). Except that the most valuable feature to me, signature help, seems not to do anything. All my tries ended in "No signature help available". The log shows that typst-lsp sends an empty answer.

As a first step, does someone have a small example where they've got signature help working? Just to be sure I've not just been unlucky with my choice of functions :) Any other insight would be welcome as well, of course. Thanks!