Amazon SP API - createFeedDocument - php

Question

The goal is to do a "POST_FLAT_FILE_PRICEANDQUANTITYONLY_UPDATE_DATA" so right now I'm trying to do a createFeedDocument which I believe is the 1st step.
There's few questions about this but none in PHP curl.
I spent hours....HOURS and still can't figure it out..
I get error:
"message": null,
"code": "InvalidInput"
I even tried removing "contentType" from the URL and put it in the header, but then I get error msg: The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method."
Please....please is there anyone out there that knows what I need to change with code below?
<?php
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => 'https://sellingpartnerapi-na.amazon.com/feeds/2021-06-30/documents?contentType=text/tab-separated-values;charset=UTF-8',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_HTTPHEADER => array(
'Accept: application/json',
'x-amz-access-token: the token<hidden>',
'X-Amz-Date: 20230125T073105Z',
'Authorization: AWS4-HMAC-SHA256 Credential=The_AccessKey/20230125/us-east-1/execute-api/aws4_request, SignedHeaders=accept;host;x-amz-access-token;x-amz-date, Signature=a6e8bdf306ea24438978a5fff961d08fc65d06c10f43c782af15a6a60<hidden>'
),
));
$response = curl_exec($curl);
curl_close($curl);
echo $response;