http error 503 notification page not rendering image - http

Question

I tried a suggestion that used three headers in a 503.php page I created on the WordPress site's root directory:
header(“HTTP/1.1 503 Service Temporarily Unavailable”);
header(“Site Down for Maintenance, Status: 503 Service Temporarily Unavailable”);
header(“Retry-After: 86400”);
I used that time hoping I can get this back up in a day or two.
I also edited the .htaccess file on my hosting service site's root directory to except my own IP from the notice redirection when I type the domain so I can get into the admin area on the wp site.
I tried adding an echo line to display the company logo.
That logo is also in the site's root folder.
echo "<img src='/TU.jpg'>"
I want to add a line under the image with the company's phone number. I read that on a Unix server I can use \n to insert a line space.
Right now when a user types the domain name they are directed to this page. The three headers are rendered on the page but they include the word header, the parentheses, double quotes, and ending line semicolons in the code lines. They are all rendered on one wrapping line.
I would like to have them print without the extra code stuff on separate lines.
The logo also renders without spacing after the three header information lines, including the word echo and the quotation marks. I'd like to space them.
I tried this:
echo "<img src='/TU.jpg'>\n Company Phone: [phone]";
but no line space is added.
With some help from my hosting service tech support I edited .htacess to add these lines at the bottom:
RewriteEngine on
RewriteCond %{REMOTE_ADDR} !^10\.10\.198\.52
RewriteCond %{REQUEST_URI} !/503.php$ [NC]
RewriteRule .* /503.php [R=302,L]
the ip exception would be mine - the one here is fake
I can't pretend I understand what it is doing. I'm a php dummy. I did the Crl-K and got the back ticks to insert the code between. I did, but the full file code seems to have broken something. I tried every way I could but still kept getting the warning about code not properly formatted...SORRY. I was only able to add those final lines as properly formatted code.
I tried inserting "\n" to separate the header lines but that didn't work either.