Construction of a homology model of a homodimeric protein

Hello everyone,
I am a PhD student. I am currently trying to create a 3D structural homology model of a protein on Discovery Studio Client. I have so far created monomeric models from different combinations of templates. However, everything suggests that this protein is a homodimeric enzyme. To improve the models created, I therefore tried to create a homodimeric model from an amino acid sequence with two chains. But it is impossible for me to launch a BLAST or a sequence alignment (with the command "Align Sequence to Templates ..." in the menu "Create Homology Models" and "Macromolecules") using the sequence of this protein with two chains in amino acids. Is it possible to create a homodimeric model using Discovery Studio's Modeler? If so, what is the process to follow? Thank you in advance for your help. Have a nice day, Laureline.