Can you try to add method `getExtraParametersForStep` and use next patern?
```
def authenticate(self, configurationAttributes, requestParameters, step):
context = Contexts.getEventContext()
...
context.set("akisCaptchaImage", captchaImageB64Encoded)
context.set("captcha", captchaBase64Encoded)
...
def getExtraParametersForStep(self, configurationAttributes, step):
if (step == 2):
return Arrays.asList("akisCaptchaImage", "captcha")
return None
```