No PIN in Citroën app

I’ve recently signed up to the premium ABRP service and am trying to link it to my Citroën EV. The linking process asks me first for my Citroën user name and password. No problem there. Then it asks me for the PIN which I use in the My Citroën app. There is no PIN in that app - it just starts. The only option then is to click on the “I’ve forgotten my PIN” button, but I haven’t. I’ve only just installed the app and connected it to my car and at no point did it ask me to enter a PIN.