Hi @Puzzled and welcome.
This is a difficult and often lonely road to walk l, it has been my journey for the last 20+ years.
is a hard question to answer. And will/may vary for different people.
I used to vary my response based on accessed risk (by my assessment). That becomes very draining though. I have discovered that for us, a consistent approach has resulted in less threats. I now take every threat seriously. We have boundaries around acceptable communication. Threats of self harm are not ok.
Very hard to achieve but, again for us, not getting emotional in the response has helped. It almost became some sort of payback knowing it would hurt me.
Having a boundary of call the Dr or if I think the risk is high enough hospital without emotion. That consistency creates security for our loved ones.
And as @Former-Member mentioned, pressing for an answer, as frustrating as non communication is, often makes things worse.
Hope that helps.