How can I find the cause of this error? We’ve detected that your app is using an old version of the Google Play developer API

Question

My Google Play Console welcomes me with this message every time I log in:

We’ve detected that your app is using an old version of the Google Play developer API. From 1 December 2019, versions 1 and 2 of this API will no longer be available. Update to version 3 before this date.

How do I even find the cause of this problem? What is this even?

Somerville

But I'm not using such services. – Somerville

Sorry, I misread google play as google pay. – Leland

Hello, and welcome to SO! Does the play console mention which app is causing this (assuming you have more than one?), what do you use PS for? – Fruitage

PS? What is that? – Somerville

I have the same warning, I don't use this API – Dewittdewlap

Please post your build.grade files. Do you have set a correct minSDK Level? Do you have a very old apk in the internal, alpha or beta channels active? – Insinuating