There are plenty of questions like this on this website, but many of the answers are simply 'download it from SDK Manager'. My situation is a bit different. In gamemaker, I get this error:
BUILD FAILED
C:\...\sdk\tools\ant\build.xml:538: Unable to resolve project target 'Google Inc.:Google APIs:13'
I tried to download both the SDK platform and Google APIs from sdk manager, but it was saying that the platform was 'Not compatible with Windows' and that the APIs could not be downloaded without the platform installed.
What I did next was download the SDK platform separately and put it in \platforms, which got rid of another error about the SDK not being installed, but made a new error about the APIs not being installed. SDK Manager still didn't show that the platform was installed, so it didn't let me get the Google APIs.
Then, I separately downloaded the APIs and placed it in \add-ons as addon-google_apis-google-13. This made gamemaker say that "SDK: ok", but when exporting the apk file, I got the error above.
How do I fix this?
Thanks in advance.
UPDATE: It might be worth noting that I can test the game with my android device completely fine through gamemaker, just can't export it.
This was solved by updating Game Maker to the latest beta version. It was a bug on their behalf.