I get error please help me

Hello,

I want to get all workflow instance ids. I think the 'preview workflow instance' will give me workflow instance ids but in the 'preview workflow instance' but that time some field is required using these documents. https://docs.helloworks.com/reference/preview-workflow-instance

Please check it.

And tell me about the participants because this is required and got the error, error screenshot given below: 

Now I am using workflow_guid in place of workflow id filed. let me know if it's wrong.

The main thing is 'I want to get all workflow instance ids'.

Please help me with it.

Thanks in advance.