How to find the appropriate method in connect?

Question

Qt

I need the OK key to become working if some character appears in the line line.
I start Establishing a connection
connect(line, SIGNAL( And the textChanged(QString) method should have appeared here, but it is not there)
I watched Qt lessons, but they are old. I have Qt5.15. Maybe something has changed over time, then the question is, how can I find the necessary method, I also did not find anything in the Qt reference materials.

Answer 1

https://doc.qt.io/qt-5/qlineedit.html#textChanged