SelectPDF with Password

Hello Friends!

Is it possible to protect the pdf generated from Bubble’s selectPDF plugin?
In the documentation, user_password is available for this function. Where can I set this parameter?

Alternatively, I used Bubble’s API Connector to create the PDF and was able to successfully add the password to the file, but the content of the generated PDF file is:

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How can I fix this?
Thanks to everyone who helps!