Select one text input (out of 2) and insert text, without having to keep mouse button pressed

Dear TParsons,

The textbox does help: I am able to select either textbox and type the text I want. However, it is important for me to be able to capture the typed text. This way I can plug it into a formula to determine whether participants are close to the screen.

I have installed psychopy 2020.2.4 for this textbox. I used the following line of code to try to get the typed text:

t = Line_box.getDisplayedText()

When I try to run my routine, I only get the participant-session dialogue box followed by a grey screen that disappears after a few seconds. The runner Stdout does not give any error messages (this is a known issue: No error messages or logging output in Stdout ), so I have no idea as to how to debug this.
Could you please, give me some pointers as to how I can capture text typed in my textboxes?
Thanks in advance.

Ellen