It's the House of Representatives. That body is the origin of all taxing. The leader of the House is Kevin McCarthy. It's is ultimately on him to lead the House (or get out of other's way) in passing a tax bill. The reconciliation process allows this to occur with less bipartisan support.

The interesting part of this appears to be that the Republicans removed this from the tax code but were expected to add it back in a new form. This did not occur in time for tax bills to be due.