provider can't reach out to Opensearch domain inside a VPC

[palamvmw]

I have set up OS domain inside a VPC because I can't expose it over the internet. It looks like this provider can't work in this scenario. I think this should be mentioned in the documentation. I wasted 2 days to make it work and ended up with the error below.

Put "https://cluster-domain.com/_opendistro/_ism/policies/logstash_index_policy": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)