There are two different forms relating to injured/innocent spouses, Form 8379, Injured Spouse Allocation and Form 8857 Request for Innocent Spouse Relief. See Publication 971 for details.
The TaxAct program does not support Form 8857, Request for Innocent Spouse Relief.
To complete Form 8379, Injured Spouse Allocation, follow the steps below.
Online
Dashboard
From within your TaxAct return, click Taxes & Miscellaneous.
On smaller devices, click the menu at the top left corner of your screen, then make your selection.