How to configure submit button in php forms such that only one data is posted at a time?

How to configure submit button in php forms such that only one data is
posted at a time?

I am trying to create a php form where data in each row can be submitted
independently. I am able to create a form which looks similar to the image
below.
How to configure the submit buttons such that when pressed, the entry in
that particular row alone gets posted to the server. I am very new to PHP
Relevant php code:
while ($driverEntries = mysqli_fetch_row($driverList)) {
printf ("%s \n", $driverEntries[1]);
echo "<input name=\"subject\" type=\"text\" id=\"subject\"
size=\"50\">";
echo "<input type=\"submit\" name=\"Submit\" value=\"Submit\">";
echo "<br>";
}