"Balance too low" exception is raised for "2captcha" method

[vyahello]

Hey there, I'm trying to use 2captcha solver method with code snippet below:

from captcha_solver import CaptchaSolver

solver = CaptchaSolver('2captcha', api_key='my api key')
raw_data = open('captcha.png', 'rb').read()
print(solver.solve_captcha(raw_data))

But next issue is raised in a runtime:

Traceback (most recent call last):
  File "captcha-solver/solver.py", line 14, in <module>
    captcha.solve('captcha.png')
  File "captcha-solver/solver.py", line 9, in solve
    print(self._solver.solve_captcha(open(file, 'rb').read()))
  File ".pyenv/versions/3.8.0/envs/captcha-solver/lib/python3.8/site-packages/captcha_solver/solver.py", line 99, in solve_captcha
    captcha_id = self.submit_captcha(image_data=data, **kwargs)
  File ".pyenv/versions/3.8.0/envs/captcha-solver/lib/python3.8/site-packages/captcha_solver/solver.py", line 73, in submit_captcha
    return self.backend.parse_submit_captcha_response(response)
  File ".pyenv/versions/3.8.0/envs/captcha-solver/lib/python3.8/site-packages/captcha_solver/backend/antigate.py", line 47, in parse_submit_captcha_response
    raise BalanceTooLow('Balance too low')
captcha_solver.error.BalanceTooLow: Balance too low

I'm using python3.8 + MacOS, also here is an image i try to use (it is about 160x70 PNG)

Do you guys have any idea why that happened?