Hello,
I managed to get it working in the end! Sometimes it wasn’t appearing when I searched for it in the tools search bar and other times it did appear, so I am not sure what I was doing wrong there. The second time I ran the workflow for the tutorial it worked, however the first time it was stuck on the pore chop command for a very long time (12 hrs), so it may have been an internet issue on my end. The tutorial I used was this one: Hands-on: 16S Microbial Analysis with mothur (extended) / Microbiome (galaxyproject.org)
and I found the workflow in public workflows.