ProcessMaker Forum | BPM Workflow Simplified

How can I download the process map as an image(like png, jpg, jpeg, ....etc) via REST

ProcessMaker doesn't provide a way to download the process map. If you want to display the process map for a case inside an iframe using REST, see this post:
viewtopic.php?f=44&t=713852&p=795983&hi ... ST#p795983

If you don't want to use web services to get the session ID, then I have created a custom REST endpoint /extrarest/session-id to generate a session ID that you can attach to the URL to view the process map. See:
viewtopic.php?f=44&t=730371&p=813761#p813761
(You don't have to make the code changes in cases_OpenDocument.php and cases_OpenOutputDocument.php since that is to address a different issue. By the way, if you have already imported a old version of my extraRest plugin, then you need to first delete it and then import the new version.)

Thanks