How am I able to push .txt files to the emulator using Android Studio?
You can use the ADB via a terminal to pass the file From Desktop to Emulator.
adb push <file-source-local> <destination-path-remote>
You can also copy file from emulator to Desktop
adb pull <file-source-remote> <destination-path>
How ever you can also use the Android Device Monitor to access files. Click on the Android Icon which can be found in the toolbar itself. It'll take few seconds to load. Once it's loaded, you can see a tab named "File Explorer". Now you could pull/push files from there.
I am using Android Studio 3.3.
Go to View -> Tools Window -> Device File Explorer. Or you can find it on the Bottom Right corner of the Android Studio.
If the Emulator is running, the Device File Explorer will display the File structure on Emulator Storage.
Here you can right click on a Folder and select "Upload" to place the file
I usually use mnt - sdcard - download folder. Thanks.