Long text in multi lines

Hello

The text below a Boundary Lifeline is long and I’m trying to presented in two lines.
Clicking on the text a boundary box around is displayed. I sized the this box but the text
inside is not formatting accordingly. Releasing the mouse button the text returns to its
original format.
I can’t find anything else to do.

A connector’s text can be manipulated with the above way, producing a multi line text.

Any ideas?

Alt+Return

Thank you very much for the answer it works like a charm.