Power BI embeded <PowerBIFilter> reference

Hello,

I am trying to call a powerBI from Dynamics CRM using the contains operator.

I use the following syntax to call a report using the is operator:

<PowerBIFilter>
{
"Filter": "[{\"$schema\":\"basic\",
\"target\":{\"table\":\"BrandChildParent\",
\"column\":\"kdc_accountNo\"},
\"operator\":\"Is\",
\"values\":[$a],
\"filterType\":1}]",
"Alias": {"$a": "kdc_accountno"}
}
</PowerBIFilter>

I have tried numerous syntax variations around this tag syntax with no luck:

<PowerBIFilter>
{
"Filter": "[{\"$schema\":\"advanced\",
\"target\":{\"table\":\"vw_BrandChildParent\",
\"column\":\"kdc_AccountNoKey\"},
\"operator\":\"Contains\",
\"values\":[$a],
\"filterType\":0}]",
"Alias": {"$a": "kdc_accountno"}
}
</PowerBIFilter>

Is there a reference somewhere on how to use the <PowerBIFilter> tag? I have found a few sites but nothing covers the xml usage in detail.

It may be a data type conversion problem (or peculiar syntax to use) as a poster in this thread suggest:

https://community.powerbi.com/t5/Desktop/Power-BI-embeded-CRM-Dynamics-365/m-p/988544

But it was unsolved on how to proceed.

Thanks