Google map - infowindow in php?

Question

PHP

There is a task for markers on the map to give infowindow but it does not work. Why is the map itself integrated into php. The link to give markers is obtained without problems.

Marker link code

echo 'let apt_' . $i . ' = {lat: ' . $lat . ', lng: ' . $lng . '};';
echo 'var marker_apt_' . $i . ' = new google.maps.Marker({
position: apt_' . $i . ',
map: map,
url: "' . $link . '",
label: {
text: "' . $price . ' ' .$current_currency.'",
color: "#fff",
fontSize: "9px",
},
icon: {
url: "' . get_template_directory_uri() . '/assets/images/svg/map-marker.svg",
scaledSize: new google.maps.Size(43, 20)
},
});

marker_apt_' . $i . '.addListener("click", function() {
window.location.href = marker_apt_' . $i . '.url });';

infowindow code

echo 'var marker_apt_' . $i . ' = new google.maps.Marker({
position: apt_' . $i . ',
map: map,
url: "' . $link . '",
label: {
text: "' . $price . ' ' .$current_currency.'",
color: "#fff",
fontSize: "9px",
},
icon: {
url: "' . get_template_directory_uri() . '/assets/images/svg/map-marker.svg",
scaledSize: new google.maps.Size(43, 20)
},
});

marker_apt_' . $i . '.addListener("click", function() {
infowindow.open = marker_apt_ });';


echo 'var infowindow' . $i . ' = new google.maps.InfoWindow({
content: "' . $i1 . '",
});';

Is my code correct? Has anyone experienced this and knows how to resolve it?