Adding Dynamics Watermark to pdf

Hi Guys,

I'm trying to create a dynamic watermark to a pdf file where the content of the watermark will be taken from a flow which is created by power automate.

The thing i reached, that to add a dynamic watermark, i will need to add a JS code to the template file to insert that watermark, but the question here is that how to pass watermark value from the flow to the JS code inserted in the template pdf file?

Can I have an illestration to the process? Appriciate your help