Hi @tomaz, we don't have a good workflow developed yet for viewing visualizations within Jupyter - check out this post for a little detail:
Maybe @uria can provide some more details about their workaround.
Otherwise, we are stuck working within Jupyter's limitations, so some code like this can get you moving:
viz = feature_table.visualizers.tabulate_seqs(rep_seqs)
viz.visualization.save('foo.qzv')
!qiime tools view foo.qzv
This will open the visualization in a new tab, although YMMV depending on how Jupyter NB is configured.