There are many modules for different compression tools available for Ark. However, I couldn't find a Zstd module. (and also xz)
Is there one available?

I recently stepped over a comparison of several compression tools and was impressed that zstd had a pretty good performance in terms of compression ratio and time.

It can be found by first opening up Ark software, clicking on create new archive button, and then change the Type drop down menu to scroll down to "Tar archive (XZ-compressed)" or "Tar archive (Zstandard-compressed)". I believe Ark should be able to find those after installing packages for tar, zstd and xz on your respective linux distro.

Ah, right this works, thanks!

I'm pretty sure I couldn't open zst archive before (some error message from Ark about supported archive format), but now it works.