I am trying to make an app where the user enters some text in a textfield and then the app displays this text in front of the ar camera to the user. I positioned the text co
If you mean that you don't want the orientation of the device to change along with the rotation, then:
Go to Project > General > Deployment Info
Under device orientation, uncheck all boxes except 'Portrait'.
If this does not solve your problem and what you really want is to fix the euler angles of your text node, let me know, I'll be happy to help.