Itc100-VH manual mode with percentage

I built a HERMS system for brewing. Everything works fine except for my boil kettle.

I want my ITC100-VH to work in manual mode with a percentage. I did put run setting to 0, but can’t see how to control by percentage?

Thanks a lot for your help.

Please long press the SET button to enter the setting mode, and set the run to 0 (manual). Please long press the SET button to save and exit the settings.
Please press the SET button for about 1 second, it will enter manual mode (SV will display an 'm’ icon), please press up/down button to set the output value.
Please refer to the detailed manual: ITC-100_Manual_V1.pdf - Google Drive