Thanks for your quick response.
Still, we are using the trial version to test if it fits our needs before purchasing It and it is working well but only this issue which I explained.
This is the code sample that I am using to import the footer from the existing file.
Please see and advise me if I am doing something wrong?
//import_footer_into.docx file exist in the directory with other contents
$docx = new CreateDocxFromTemplate('import_footer_into.docx');
//import_footer_from.docx file exist in the directory with footer
$docx->importHeadersAndFooters('import_footer_from.docx', 'footer');
$docx->createDocx('import_footer_into.docx');