Does an in-app browser affect App Privacy Details declaration?

Since it's now compulsary to explain the data handling practices of your app on the App Store, I'm wondering how the data collected by an external website which is wrapped by an iOS app in an in-app browser affects this.

Our iOS app contains a purchase flow which hands off to a 3rd party webapp within an in-app browser, where users enter personal data such as name/address/email/payment details.
This data is not available/not collected by our app itself, but is gathered by that 3rd party webapp just as if the user had visited it directly in their web browser.
For clarity, the 3rd party website is presented chromeless in order to appear to the user as though it is a part of our iOS app.

So my question is, do I need to declare what/how the user data collected by that 3rd party website is used when filling out the app privacy questions for our app in App Store Connect?


References:
https://developer.apple.com/app-store/app-privacy-details/
https://help.apple.com/app-store-connect/#/dev1b4647c5b