Nested one-to-one insert in Firebase DataConnect?

I d like to insert my Product and create its name in the Localized String table in the same operation.

mutation CreateProduct {
  product_insert(
    data: { 
        name: localizedString_insert( 
            data: { 
                enUS: "MyProduct"
                frFR: "MonProduit"
        }) 
    })
}

schema:

type Product @table {
  name: LocalizedString
}

type LocalizedString @table {
  enUS: String
  frFR: String
}

I tried so many ways but none seems to work, do DataConnect even allow one-to-one nested insert or should i do like a 3 operation inserts for each row?