Welcome to the developer community Bob!
Unfortunately, our V3/beta APIs don’t yet support the retrieval or updating of account correlation configuration on a source.
You can read this post on how to get the config: Account Correlation API (ACCOUNT_CORRELATION_CONFIG) - #3 by colin_mckibben.
However, the only API that can set the config is internal only. I have this functionality on a list of items for our product team to look into providing.