Hi @mobar,
Welcome to the :qiime2: forum! I moved this to community plugin support, since the q2-ancom-bc is a community plugin rather than a core release. (It can be a llittle confusing.)
As far as I know, the ANCOM-BC plugin has not been released and is still in testing. However, based on where things are failing, what does your metadata look like?
Best,
Justine