Recently, Google announced that the contribution feature was turned off.
ref. What’s new in Google Translate: Changes to Contribute - Google Translate Help - https://support.google.com/translate/answer/14754103?sjid=4013565532041901992-AP
It'd be nice that the description about the contribution for Google Translate is updated. It seems that they still accept the bug reports other than the contribution about the translated text.
Thank youǃ