Howdy Giraffentoaster,
I found another post where a user was having the same issue. Deploying to Android from the Mac is not currently possible with UE4. It is something we’re definitely planning for, and while we hope to have it this year, we do not have a specific time frame for it yet.
Here is a link to that other post as well: https://answers.unrealengine.com/questions/107972/why-should-i-continue-my-subscription.html
Thanks and have a great day!