SEND TO NOTION - ERROR

I get this error when trying to add data with Pabbly to a "Person-field" in Notion
I have no team members, only guest but I want to @name tag one of my guest everytime pabbly adds a record, so he will get a notification, but I got this error
"should be a valid uuid"
Where do I find the person uuid
I have 0 idea of API ?

Hey @Pere

As we can check your Workflow's history, it seems like you might have passed the entity with @xxxxxx, but as we can see in your workflow the respective field is not mapped.

Could you please elaborate on what has mapped over there, so that we can assist you accordingly? Also please share the workflow name as well so that we can review it once.

Thanks Supreme :-D
The field is not mapped because if I try to map it with the notion guest name (@Rubén Arcas) for example, I get this erro (see image on first message). This is why I don't map this field.
I would like to tag a guest so he receives a notification on notion, this is why I am trying to map it.
In notion I have guest, not members.

SMARTNET - COMPROBACIÓN DE IDENTIDAD - AIDA > NOTION
Do you need I "share" with you the workflow?

Hey @Pere

Could you please share any reference of adding a tagged member through the API(@xyzqwe) in any platform, so that we can also implement the same?