GD has an extension named “Text entry” (Native Platform)
You can add the Text Entry object to the scene (is invisible) and des/activate the text input capture, the object save the captured text in a string. Then you can use the string for whatever you want 
Example 
(left click to des/activate the text entry):
Note: variable checkNext is my “elif or else if”, other way GD will read:
Text entry is desactived ===> Activate it
Text entry is now activated ===> Desactivate it 