Add custom xmp metada

Hi,
I found some older tickets with adding custom xp metadata to pdf files. the links to the documentation in this tickets are not vaild, so I hhave to ask:
It is possbile to add custom xmp metadata to a pdf file? I only found adding or modifying predefined metadata to a pdf file.
regards
Jörg

@de14jne

Thank you for contacting support.

Please visit Working with Document for your kind reference.

We hope this will be helpful. Please feel free to contact us if you need any further assistance.

Thank you.
regards
Jörg