Typeorm (Nestjs) update ManyToMany relation when using querybuilder violates not-null constraint

I have a simple ManyToMany setup with typeorm. According to the docs of typeORM on how to update/add a ManyToMany relation.

Link to the docs: https://typeorm.io/relational-query-builder

The error I get:

The query it produces, and here is the problem, it does not have 2 parameters and 'usersId' is empty. I think the user has to exist first before connecting them together, but maybe someone can confirm this? Why does it not create the user for me when adding a new user in enterprise?

query: SELECT "Enterprise"."id" AS "Enterprise_id", "Enterprise"."createdAt" AS "Enterprise_createdAt", "Enterprise"."updatedAt" AS "Enterprise_updatedAt", "Enterprise"."name" AS "Enterprise_name", "Enterprise"."erpCustomerCode" AS "Enterprise_erpCustomerCode", "Enterprise"."isActive" AS "Enterprise_isActive", "Enterprise"."street" AS "Enterprise_street", "Enterprise"."houseNumber" AS "Enterprise_houseNumber", "Enterprise"."city" AS "Enterprise_city", "Enterprise"."state" AS "Enterprise_state", "Enterprise"."country" AS "Enterprise_country", "Enterprise"."zip" AS "Enterprise_zip", "Enterprise"."geoLocation" AS "Enterprise_geoLocation", "Enterprise"."unitsSystem" AS "Enterprise_unitsSystem", "Enterprise"."weekNumberingSystem" AS "Enterprise_weekNumberingSystem", "Enterprise"."yearStart" AS "Enterprise_yearStart", "Enterprise"."weekStart" AS "Enterprise_weekStart" FROM "enterprises" "Enterprise" WHERE ("Enterprise"."id" = $1) LIMIT 1 -- PARAMETERS: ["d2f16db8-63be-4b09-a5ea-e04336069df4"]
User {}
query: INSERT INTO "enterprise_users"("enterprisesId", "usersId") VALUES ($1, DEFAULT) -- PARAMETERS: ["d2f16db8-63be-4b09-a5ea-e04336069df4"]
query failed: INSERT INTO "enterprise_users"("enterprisesId", "usersId") VALUES ($1, DEFAULT) -- PARAMETERS: ["d2f16db8-63be-4b09-a5ea-e04336069df4"]

I have the following setup:

enterprise.entity.ts

@Entity('enterprises')
export class Enterprise {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @CreateDateColumn({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
  createdAt: Date;

  @UpdateDateColumn({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
  updatedAt: Date;

  @Column({ unique: true, length: 50 })
  name: string;

  ...


  @ManyToMany(() => User, (users) => users.enterprises, { cascade: true })
  @JoinTable({ name: 'enterprise_users' })
  users: User[];
}

user.entity.ts

@Entity('users')
export class User {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column()
  name: string;

  @ManyToMany(() => Enterprise, (enterprise) => enterprise.users)
  enterprises: Enterprise[];
}

enterprise.service.ts

@Injectable()
export class EnterpriseService {
  constructor(
    @InjectRepository(Enterprise)
    private enterpriseRepository: Repository<Enterprise>,
  ) {}


  async update(id: string, enterprise: UpdateEnterpriseDto) {
    
    // for testing
    const user = new User();

    user.name = 'test123';

    // triggers error
    await this.enterpriseRepository.createQueryBuilder().relation(Enterprise, 'users').of(id).add(user);

 
    return this.enterpriseRepository.save({ id, ...enterprise });
  }
}