What is the simplest way of working out how many representative sequences exist in each sample of a QIIME2 experiment?

I understand that I can obtain the total number of rep-seqs (or what used to be called OTUs) across the entire experiment, and the taxon (if any) that they are applied to, but for the life of me I can’t work out a simple way of finding out how many total rep-seqs exist in each individual sample (since some rep-seqs occur in some samples but not others).

Thanks for your help.