Different versions of Mandarin, the screenshot function is in different places. But basically, you can click the right mouse button in the K-line diagram, and then check whether there is the word "screenshot" in the pop-up selection. If not, if I remember correctly, some versions are in the "Other" section of this interface.

Or you can click on the top menu bar (trading, quotation, arbitrage, ... help) and look for "screenshot" or "other" in it.

In Winsun, you can also try to save this button, which seems to be ok.