How to set upload file data in GraphQL variables?

I want to create a GraphQL API for file upload feature. Now using graphql-upload library for a data type.

import { GraphQLUpload, FileUpload } from 'graphql-upload';
import { InputType, Field } from '@nestjs/graphql';

@InputType()
export class FileInput {
  @Field()
  id: string;

  @Field(() => GraphQLUpload)
  file: Promise<FileUpload>;
}

The input data type:

@InputType()
export class CreateProduct {
  ...

  @Field(() => FileInput)
  picture: FileInput;
}

This is mutation:

mutation createProduct($input: CreateProduct!) {
  createProduct(input: $input) {
    success
  }
}

This is variable

{
    "input": {
        "id": "1111",
        "name": "Big",
        "picture": "",
    }
}

The picture data is an upload file. How to set data in it to call the API? Is it set full path like /Users/aaa/Pictures/product.png?