Adding existing BP to a CRM Lead via BAPI_LEAD_CREATEMULTI

Hi All,

I am very new to CRM and I have a scenario where leads are already created in CRM but now I am required to add additional BPs(already existing) as sales prospects to the lead. At the moment I am finding some difficulty adding the BPs to the lead, which fields are required(or are mandatory) for this to be successful?

Below I am running the BAPI via se37 to test, all my (structures) have been marked accordingly.

I have added data to my header which provides data for my already created lead

And when I debug, I see that it splits the header into another lead structure. I then populated my partner structure with the below,

My return table returns the below but it still fails when I enter a REF_GUID which I enter as the BP GUID.

I was also wonder what a logical_key is and what the purpose of a ref/handlers are.

Your assistance will be much appreciated, thank you.