Parse Platform Graphql Batch Update

im getting a problem when using graphql in parse platform

i want running a multiple mutation update with single mutation or batch. i have success when creating data, but for updating data im getting error.

im try like this

mutation ($objectId1: ID!, $objectId2: ID!) {
  update1: updateCourse(
    objectId: $objectId1
    fields: { title: "HEBOH", slug: "HEBOH ITU KEREN ANJIR" }
  ),
  update2: updateCourse(
    objectId: $objectId2
    fields: { title: "HEBOH", slug: "HEBOH ITU KEREN ANJIR" }
  )
}

anyone can give me an example for this? Thankyou