Hi,
I am getting the same error and i also was able to connect using opensearch-py.
I also founded in this doc https://github.com/opensearch-project/opensearch-hadoop/blob/main/README.md#requirements that i need to have some jars i already add it without any luck and here it mentions another jar i already added https://github.com/opensearch-project/opensearch-hadoop/blob/main/USER_GUIDE.md#signing-requests-for...

I am using service credential to access OS not instance profile, is this make a difference ? and if someone can help it will be highly appreciated