I don’t think that I can provide for you access to the admin panel. But I think I can describe my idea more detailed.
As I understand ‘Amazon Polly’ takes text only from 2 fields in the admin panel:
1) post title (input field);
2) post body (wysiwyg).
For example, I want to add an additional textarea (maybe with the help from the ACF plugin) with the name ‘About author’. So in the admin panel this will be 3rd field. But ‘Amazon Polly’ does not work with another fields yet.
And on the front side page will be contain text from the post ‘Title’, post ‘Body’ and additional field ‘About author’. But ‘Amazon Polly’ will voice only post ‘Title’ and post ‘Body’.
So I want to have ability to voice additional text fields. I guess I clearly described my wishes for you. ??
Another way is to put text of the ‘About author’ to the post ‘Body’ but this decision will not work for me.