According to Alberta AT1 return rules [click this link], A complete return can be filed in one of the following formats:
i) an AT1 and applicable schedules; or
ii) Alberta return and schedule information (RSI); or
iii ) Alberta Net File return.
Before T2Express v2015.1, AT1 RSI print and Netfile function by T2Express has not been approved by AB Finance. A solution could be that you just mail those AT1 client copy pages generated by T2Express software.
Since T2Express v2015.1, AT1 RSI print and Netfile was certified and available in T2Express software. You can do the filing as you want. You can read this link for more information.