The problem is that your JSON includes a '
character which is the same character you are using to delimit the string.
The simplest solution to this is to treat the JSON as JavaScript (the data format is a subset of the programming language).
let data = <?php echo json_encode(["name" => "cote d'ivoire"]) ?>;
If you really want to generate a string of JSON which you can then parse, then the best tool to escape the special characters in it is json_encode
(which will also add quotes around it for you, so you don't need to do that manually).
let json_data = <?php echo json_encode(json_encode(["name" => "test"])); ?>;
let data = JSON.parse(json_data);