short answer
“C:\Program Files (x86)\Mobatek\MobaXterm\MobaXterm.exe” -dpi 140
Detailed answer
As of now (January 6, 2023), the latest v22.3 version of MobaXterm has not provided the function of modifying the font size of the software itself in the software interface (only the function of modifying the font size of the terminal inside is provided), you need to modify The font size of the software itself needs to provide parameters when opening the software.
It is assumed here that you open the software by double-clicking the shortcut.
Step 1, find your shortcut -> right click -> properties
Step 2: Add parameters in Target -dpi 140
Note that .exe" -dpi
there are spaces in between and -dpi 140
spaces in between.