Upload file without timestamp prefix and overwrite server file

The file upload in the view section of the start_page, along with submit button, works fine. Uploading works as well and the filename is prefixed with a timestamp and in a special directory I defined in Form Settings (used *** for privacy reasons).

My requirement is that the filename should be without the timestamp prefix and in case the file already exists on the server, this file is overwritten by the new uploaded version.

I tried the file upload action on the end_page, used several CF6 forum posts, but I do not get it to work.
Please find the debug of the end_page.

Could someone help me with these two requirements?

Array
(
    [option] => com_chronoforms7
    [cont] => manager
    [chronoform] => form-13may23-2132
    [gpage] => end_page
    [__cf_token] => c49d10ad-1f46-43d3-b815-ad8f1de0d22e
)
Array
(
    [end_page_upload] => Array
        (
            [path] => /var/www/clients/client1/web2/web/images/****/declaratiegastpredikant/
            [file_1] => Array
                (
                    [extensions] => Array
                        (
                            [0] => pdf
                        )

                    [saved] => true
                )

            [var] => Array
                (
                    [file_1] => Array
                        (
                            [path] => /var/www/clients/client1/web2/web/images/****/20230514201614_testfile.pdf
                            [filename] => 20230514201614_testfile.pdf
                            [name] => testfile.pdf
                            [size] => 67057
                            [url] => https://test.mydomain.nl/administrator/load&dtask=download&file=20230514201614_testfile.pdf
                        )

                )

        )

    [end_page_validation] => Array
        (
            [log] => Automatic validation enabled.
            [var] => true
        )

    [upload_5] => Array
        (
            [path] => /var/www/clients/client1/web2/web/images/****/declaratiegastpredikant/
            [file_1] => Array
                (
                    [extensions] => Array
                        (
                            [0] => pdf
                        )

                    [saved] => false
                )

            [var] => false
        )

)