Error on writing INT to register

[T1NBK]

I get an error while trying to send an integer value from a selector type switch to a register.
It look to me it wants to write a str to the register?

Error:
2020-05-31 21:13:33.964 Error: (EASY WTW stand (write)) 'onCommand' failed 'TypeError':'can only concatenate str (not "int") to str'.
2020-05-31 21:13:33.964 Error: (EASY WTW stand (write)) ----> Line 306 in '/home/pi/domoticz/plugins/modbus-write/plugin.py', function onCommand
2020-05-31 21:13:33.964 Error: (EASY WTW stand (write)) ----> Line 222 in '/home/pi/domoticz/plugins/modbus-write/plugin.py', function onCommand

Hardware:
Type:
Modbus RTU / ASCII / TCP/IP - WRITE v2020.2D

Set-up and Configuration:
Communication Mode:
TCP/IP (+DEBUG)
RTU - Serial Port:
/dev/serial0
RTU - Port settings:
StopBits 1 / ByteSize 8 / Parity: None
RTU - Baudrate:
9600
TCP/IP - IP:Port:
192.168.8.201:502
Device ID:
1
Modbus Function:
Write Single Holding Register (Function 6)
Register number:
2032
Payload ON:
Payload OFF: