Nothing happens when click on 'Fill'

Hi.

Using Power Automate Flow, I read a pdf from a Sharepoint folder, then send the file to Adobe Sign using "Create an agreement from an uploaded document and send for signature" action.

When the flow finished running, I can see the file under "Waiting for you".

However, when I click on 'Fill' button, nothing happens.

At this point, how to proceed to sign the document?

Thank you.