On August 16, the national Working Families Party announced that its members had voted to endorse Hillary Clinton for President. See this story, which says she won 68%. Most who did not support her chose “no endorsement”. The endorsement process is separate from the nomination process, and each state Working Families Party that is on the ballot will decide whether to nominate her. In the past, the only state unit of the Working Families Party that has nominated anyone for President is the New York WFP.
It is possible that the WFP of Oregon and South Carolina will put Hillary Clinton on the ballot as their nominee. The Connecticut WFP will not, because that would have meant gathering 7,500 valid signatures, which the party did not attempt.