How to turn on HiDPI mode on external display in macOS

When the Mac is connected to a high-resolution 2K monitor, for example, the DELL U2518D of mine has a default resolution of 2560*1440, which is stuffed into a 25-inch screen. The text is actually a bit small. But what I want should be: If you directly use the Scale method to lower the resolution, for example, to 1080p: In this way the text is large, but the edges will be