How to excule a particular value while imploding

Question

Array
    (
        [merchant_id] => ece6ba4ec4db93924d070b4c13b
        [invoice_id] => 1772fb6eafda04ceb11c77cf719a347f
        [invoice_created] => 1634467789
        [invoice_expires] => 1634469589
        [invoice_amount] => 10
    )

Here implode takes all the values. How to skip a particular value invoice_amount value from the output.

echo implode("&",$_POST);