I am testing an endpoint for image upload with jest and supertest but I keep getting the error " expected 200 ok status but got 400 bad request"

here is my code

test('should upload an avatar', async () => {
  await request(app)
    .post('/users/me/avatar')
    .set('Authorization', `Bearer ${user1.tokens[0].token}`)
    .attach('avatar', 'tests/fixtures/profile-pic.jpg')
    .expect(200);
});