Xero Filter when watching bank transactions

I’m having a lot of trouble adding the correct filter syntax on the “Watch Bank Transactions” on Xero to only watch for a specific Contact. I’ve been trying to use their API documentation but can’t figure out the correct syntax to set a filter for just one particular contact ID

Hi there, did you manage to figure this out? I can’t see examples of how this should work at all?
All I could see was this one example on the xero make documentation. And it yielded zero results when I tried it.
Type==“BANK”