Hello Ori Bandel
Sorry for the confusion. I misunderstood it earlier.
From the document:
The left anti-join flavor returns all records from the left side that don't match any record from the right side. The anti-join models the "NOT IN" query.
Aliases: anti, left anti-semi
The "anti" join and the "leftanti" join are equivalent, and both return all the rows from the left table that do not have a matching row in the right table.
https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/join-leftanti