I am filing a corporate return for the province of Alberta. Do I need to do the submission to CRA only?

In this case you will need to complete two separate transmissions, federal and provincial. When you are ready to transmit your corporate tax return, first go to 'Transmission' on the menu bar and click on 'Transmit CIF' to transmit the return to CRA. After having received the confirmation of successful transmission to the CRA, go back to 'Transmission' and click on 'AT1 Netfile' to do the provincial transmission.