Benedetta says, if you want to use semolina it's ok, if you don't want to, it's ok as well. You can use flour type 0 or 00 or half normal flour and half Manitoba flour. We don't have it here as far as I know.

Bottom line, she's using semolina to make the dough more soft, puffy. But she also says you can leave it out. So no worries.

I used to make focaccia with all purpose flour, or normal bread flour, so it is ok.