Why cannot retrieve or launch a Workflow Job Template via Tower API?

I tried to launch a Workflow Template on Ansible Tower by calling the APIs. But cannot even get the template information using https://towerIP/api/v2/job_templates/workflowtemplatename. No matter to launch it. It works fine with those Job Templates. Does anyone know why it cannot work?

Thanks.

This isn’t the list for Tower (AWX is the upstream open source project) development. You should look for help on the awx-project mailing list here: https://groups.google.com/forum/#!forum/awx-project.