Alarm Sound Generator Module

My "Siren" seems to be a Clipsal Horn (I am assuming similar to a megaphone) thus connected the siren output to it gives me the same output as place DC on a normal speaker.

My request is to add a (perhaps external) component like the UM3561 IC for scenarios like that which I can just plug and play. Even if it is its own separate mini PCB. I don't want to replace the entire siren and strobe light just because of that.