How can I insert images dynamically into adobe sign template via power automate

I would like to add images dynamically into Adobe sign template (word/pdf doc in my case) via power automate. 

Goal is to populate company owner's signature as an image in agreement template and send the doc for signature. We are achieving everything with power automate but inserting images does not seems to be working.

As per Adobe blog, it should be possibe:

https://www.adobe.io/document-services/docs/overview/document-generation-api/templatetags/#images