OnePlus 6 - Havoc 4.19 - Deactivate incoming calls when using Dual SIM

Hello!

I use Dual SIM on my OnePlus 6 running Havoc-OS 4.19 (Android 11). I have one SIM for Data and one SIM for calls. Now I want to disable incoming calls on my Data SIM, but I can't find the options to set this up. Is this possible? Any help would be very much appreciated! Thank you!