How to make a specific callers route directly to voicemail?

How in the world do you route a specific caller/s directly to voicemail?

i’ve seen suggestions of applying a silent ringtone to specific contacts but that is not an an option in iPhone because it doesn’t come with a silent ringtone. And we should not have to pay $2 for silence on the App Store. I don’t want to block the callers because Apple support said I won’t get their voicemails if I do that.

and I don’t want to turn my entire phone on do not disturb that blocks everyone!!

This is my first iPhone and it is the most annoying phone ever with ridiculously limited features that have been around forever on android phones.

This should be simple, it’s 2022!