Uncaught SyntaxError: "" string literal contains an unescaped line break _install.php

I could install version 5.2.0 fine. All the requirements are met and it does create all the tables and fills in the login table with the initial user.

So back to the issue installing 5.2.3: I get to this stage:

Great. Looks like your server is configured perfectly to run Sendy. :)

On the install page I see in the console:

Uncaught SyntaxError: "" string literal contains an unescaped line break _install.php:235:19

when I click the error link it shows me this highlighted line:

url = "https

which is in:

//Change the appearance
function change_appearance(mode)
{
    $("#dark_mode").val(mode);
    url = "https
://mydomain.com
/includes/helpers/appearance.php";
dark_mode = $("#dark_mode").val();

$.post(url, { dark_mode: dark_mode },
    function(data) {
    if(data)
        location.reload();
    else
        alert("Unable

when I enter the details and click install the page refreshes and empties the fields. now in the console shows:

Uncaught SyntaxError: "" string literal contains an unescaped line break _install.php:178:24

</div><script type="text/javascript">window.location = "https
://mydomain.com
/login";</script><hr>

Uncaught SyntaxError: "" string literal contains an unescaped line break _install.php:237:19

url = "https

(this error is the same as the first one, which shows the first time the install page is shown)

When I just go to mydomain.com it shows the sendy bar on the top with the settings button and profile button, but nothing in the main part of the screen. The console error says:

Uncaught SyntaxError: "" string literal contains an unescaped line break mydomain.com:121:24

 <div class="container-fluid">
        <script type="text/javascript">window.location = "https
://mydomain.com
/login";</script>

Is the issue something to do with the config.php?: define('APP_PATH', getenv('SENDY_PROTOCOL') . '://' . getenv('SENDY_FQDN'));

When I copy the error it shows the link like this with spaces:

https ://mydomain.com /login

bubbajames-docker / sendy

Uncaught SyntaxError: "" string literal contains an unescaped line break _install.php #8