Error while connecting user Id of the creator to a created post

I’m facing a problem. When I create a post and try to connect the user id of the creator to that post, I get this error:

Here is the schema:

type Post {
  title: String!
  description: String
  images: [Image!]
  videos: [Video!]
  type: String,
  createdBy: User!,
  likes: [User!],
  comments: [Comment!]

Does the User with this ID exist? That error message is saying you’re creating a new User so you must provide all required fields of the user. Double-check the ID.

The system thinks the user with the ID you gave does not exist.

If the ID does not exist then it will try to create the User. In this case, all required fields must be provided.