Am I supposed to be able to use Google Play services for IAP?

Please excuse me if this is not the correct forum to post this in.

Everywhere I have looked I have found that you are not able to do IAP with the /e/OS App Lounge, which is fine by me. I don’t typically use IAP.

Yesterday, I was playing Creatures of Aether on my phone, and out of curiosity I tapped on one of the IAP in the shop to see what would happen. To my surprise, I was prompted to add money to my Google Play account to complete the purchase. Tapping on one of the payment methods brings up the Payment & subscriptions page of the Google Play store, but within the Creatures of Aether app.

I have a Google account added in my phone through microG. Does this have something to do with it? The file name of the first two screenshots contains “microG_Companion” and the third screenshot has “BlissLauncher”. Is someone able to explain what is going on here? Thank you!

Imgur album since I’m a new user so I can’t embed images.

In case it helps inform, this is a search of IAP, Open and Closed issues at microg, GmsCore

microg implements some(?) of the IAP surface, you should be able to do a purchase through it. The wiki status doesn’t list Billing / In App Payments at all, but the help text in the microG settings suggest you can do a purchase - I never gave this any test so unsure if it can be taken at face value.

Thank you for the reply, I believe that’s what’s going on. I was looking through microG settings on my phone and found that this is an experimental feature for handling billing requests for Google Play that can be turned of/off. To test, I disabled the setting, and low and behold, none of the IAP purchase options in Creatures of Aether are even visible, and when I try to click the “+” next to the in-game currencies to purchase more, nothing happens! So it looks like that setting is why I was able to purchase things using Google Play before.