How to translate an echo in PHP with Javascript?

one text

I have a HTML site and I made a toggle that changes the language without refreshing the page (with Javascript), I just assign an ID and that's it, as you can see here:

var strings = {
    espanol: {
        //PRINCIPAL//
        lang: "<i class='fa-duotone fa-earth-americas fa-lg'></i> Idioma",
    },
    english: {
        //PRINCIPAL//
        lang: "<i class='fa-duotone fa-earth-americas fa-lg'></i> Language",
    }
}

$( ".espanol" ).on( "click", function() {
    // update to espanol
    localizeStrings('espanol');
});
$( ".english" ).on( "click", function() {
    // update to english
    localizeStrings('english');
});

// default language 
var Lang = "espanol";

// localize with default language
localizeStrings(Lang);

// update selected language   
function localizeStrings(strLang) {
    $(strings[strLang]).each(function(key, lang){
        $.each(lang, function(id, string) {
            $("#"+id).html(string);
        });
    });
}

To well there, but a part of my web, returns to a an echo of a PHP file.

So I have no idea how to translate it, could you help me? I am new to this.

Normal (HTML) translation:

<a class="nav-link dropdown-toggle" role="button" data-mdb-toggle="dropdown" id="lang" aria-expanded="false"></a>

PHP echo that I want to translate:

echo '{"error":-1, "msg":"<font color=#B23CFD><b>Unknown</b></font> | '.$text2.' -YES"}';

Thanks in advance.