How to connect to Raspi4

Spec
* Raspberry Pi 4 Model B (4GB)
* Raspberry Pi OS (32-bit)
* Keithley 2611B
* Connected physically by LAN cable

How can I connect Keithley2611B to Raspi 4?
I tried as below code, but Raspi cannot find the device, like 'TCPIP0::0::192.168.0.2::INSTR'.
``` python
import pyvisa
rm = pyvisa.ResourceManager()
rm.list_resources()

>> ('ASRL/dev/ttyAMA0::INSTR', )
```
