P4 ProV2: How connect to DJI Assistant 1.1.2 ?

Hi,

does anyone know what to do for connecting P4V2 to “old” DJI Assistant 1.1.2. I have firmware 1.00.00.
My P4ProV2 doies not connect to Ass 1.1.2
Have I to use an even older firmware version and where I can get it? Does anyone have an idea?

Regards,
P4 Fan