How can I permanently set the preferred mode for Braille Screen Input?

Hello,
I use everyday and for everything the Imput Brialle for writing in my Iphone. I use always the "Far screen) mode (so not the table mode, but the other), and I have always this blokecd. Today, I don't know how and why, it's unblocked, and I would like to block it again in order to avoid that the mode change when I move the telephone. I know that there is a gest in imput Braille to do it, but unfortunately I cannot remember, pelase, could someone help me and tell me how is this finger movement?.
Many thanks in advance.
María