Function of RI in quectel EG25-G

What is the function of RI pin in quectel EG25G? Can it be left Open?

The RI pin is an output ringing prompt. At the same time, when the module has a URC report, the RI signal will wake up the host. For specific functions and configurations, you can check the module hardware design manual.
Quectel_EG25-G_Hardware_Design_V1.4.pdf (1.3 MB)