Not sure if it's something with our configuration but I'm unable to use that syntax. I get an error at the ! in Graphiql. So it seems I'm limited to the syntax described here https://experienceleague.adobe.com/en/docs/experience-manager-65/content/assets/extending/graphql-api-content-fragments#filte...

I'm looking for a way to have an optional filter on graphql persisted queries for content fragments. It seems like it was possible at one point to define a variable for the query and, if it had no value, the filter would be ignored and all results would be returned. This is exactly the functionality...