how to use "Create PDF"(Existing Document)

Please tell me how to use "Create PDF".

I would like to overwrite data on an existing PDF and create a new PDF.

Therefore, I implemented the following processing.

・Copy Template PDF: Create a copy version of the base PDF and store it in "pv!copyTemplate"

・Edit PDF Name: Change the name of "pv!copyTemplate"

・Create PDF: Each parameter is set as below.
Create New Document: false
Existing Document: pv!copyTemplate
Pause On Error: false
Contents: (describe the contents as an expression)

No values ​​are set for any parameters not listed above.

This is the PDF to copy from.
I have confirmed that the content is retained even after the "Edit PDF Name" process is completed.

However, when the "Create PDF" process is finished and you check the contents of the same file, it looks like the following.
The value set in the parameter "Contents" is listed, but the PDF that was supposed to be set in "Existing Document" is not reflected.

What should I do now?