How can I find table with Document Header Notes/Text

Hello Experts

I hope you will be able to help me to locate from which table I can get Document Header Notes/Text

to be more specific ... I'm running Power Query connected to SAP table and I want to get text which is put into Header Notes of PR or PO

How can I locate this texts and get them loaded into excel spreadsheet?

for instance if PR Header Note says "will be used for project No. 1234" from which table I can get this text (tables in Power Query) and load into excel?

I would really appreciate for your support

thanks