PHP Code Help fix php code to update database

PHP Code Help fix php code to update database

I am new to php and spent hours trying to get some code to work, looking for someone to fix my code so that it works..I have the code below, I am trying to get it to show a random url in an iframe, which i have working...However, for the life of me, I cannot get it to update the associated row and deduct 1 credit.
So, this job is for $15 for someone to fix my code so that it pulls a random url from database and puts it in iframe, and then deducts 1 credit from the ID / row that it pulled the url from.

Below is the code I have...

<?php

include 'config.php'; ?>

<?php

$result = mysqli_query($conn,"SELECT id, url FROM oto_msites order by RAND() limit 1"); ?>

<?php

$i=0;

while($row = mysqli_fetch_array($result)) {

>

<?php

mysqli_query($conn,"UPDATE oto_msites SET credits = credits-1 WHERE id = echo .$id."); ?>



<main>

<iframe border="0" frameborder="0" height="100%" width="100%" id="banner" marginheight="0" marginwidth="0" scrolling="yes" src="<?php echo $row["url"]; ?>"></iframe>

</main>

<?php

$i++;

}

>

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Requirements

Get the php code working so that it pulls random url from database to show in iframe and then deducts 1 credit from the id / row that it pulled url from.

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Skills Required

php