There are some options to do that. But it is not so simple and quick as one can expected. It is not working out of the box and you will usually need to compile some stuff by yourself (Custom modules for C++ and Creating Android modules)
Here are some links that you can find useful:
IAP Android Post on old forum about this topic.
Mentioned modules are placed in platform/android/java/src/org/godotengine/godot in source of Godot.
Now you can’t add module through editor. You have to edit engine.cfg and add there
I’ve used the Chartboost one and worked fine. Both need an upgrade to 2.0 though.
Shin-NiL | 2016-02-28 14:24
Thanks! I added it to the list.
lukas | 2016-02-29 14:57
Hi. Could you explain what has to be done to enable Android IAP? I added this android/modules string to my project config but what I have to do to use GodotPayment? I also found GodotPayment.java on github but I’m not sure what I should do now. I mean how to compile in this GP into the engine. Should i download whole source code, compile it and then use it to build my APK?
Xardanves | 2016-03-20 12:30
I recommend to post it as a new question. I am not an expert in this field, so since it also interested me I hope that someone with more knowledge will post an answer.
I think that now the Android export template is compiled with this module inside. So there is no need to download and compile source by yourself (as I wrongly stated in the answer - I will edit it). If you add the string to engine.cfg, you can use all the functions mentioned in the old forum post. And I also think that to test it you need Google developer account to get your app ID.
lukas | 2016-03-20 13:07
I’m afraid there is something more what has to be done or i just did something wrong because when i call Global.get_singleton(“GodotPayments”) i receive a null object… I run app on PC and not Android when testing it so maybe this is the problem.
It also would be nice to know how to use this API. How can i initialize purchase and so on. I will create new thread just like you said.