I haven’t tried it myself yet (and leave this comment as a kind of reminder to myself), but maybe the manual setup creates the PostrGes configuration anyway, when entering the proper info.
A video that details the pg setup for a strapi 3 install can be found here: Getting started with Strapi Headless CMS on mac with PostgreSQL [ strapi tutorial ] - YouTube
So I assume the steps to go would be:
- setup pg
- setup strapi4 manually (that is: NOT quickstart)