The Apex Walther PPQ Forward Set Trigger, as stated by the manufacturer, has not been tested with the Walther PDP. I would recommend reaching out to them directly for more information. Their contact info can be found linked below:
https://www.apextactical.com/contact
Yes it will work in a pdp. Walther arms if you send the apex trigger will install it for you
I was bored one night and tried to put the Apex trigger for the PPQ in my PDP compact and it fits and works properly.