Board Game Arena

If you know that someone didn't pass a room, you want to write down the letters with an X through them. Is it possible with the BGA version?

It's a little cumbersome, but after you start typing, you can click on the blue box beneath it (that looks like a t or + symbol). You have to have some text there or it just moves the starting point for the box. Does that make sense? If not, I'll try to do some screenshots to make it clearer