Screencast text box without timeline limit

I'd like a text box to stay on the slide forever with step-by-step instructions. It is set automatically that a text field only 3 seconds appears (but that is too short to read it). Although I can choose "Always Show" for a textbox, the text box disappears after the timline of the slide Ends. But i would like to appear the text box without any time limit of 3 sec, 20 sec or something else. Are there any solutions?