how to correct charset in pdo php pgsql

My query executed in PDO (PHP, pgsql) using (LIKE) do not query the regists with (ñ,´), i triyed with this in HTML:

<meta charset="utf-8">

And this in PHP:

    header("Content-Type: application/json; charset=UTF-8");

    public static function connect(){
     $options = array(
        PDO::ATTR_PERSISTENT => true,
        PDO::ATTR_EMULATE_PREPARES => false,
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
    if (null == self::$cont) {
        try {
            self::$cont = new PDO("pgsql:host=" . self::$dbhost . " options='-- 
            client_encoding=UTF8' ;port=" . self::$dbport
            . "; dbname= " . self::$db, self::$dbuser, self::$dbpass . "", $options);
        } catch (PDOException $e) {
            die(" ERROR POR CONEXIÓN " . $e->getMessage());
        }
    }
    return self::$cont;
}

  $pdo = Database::connect();

  $criterio = "%" . mb_strtoupper($filtro) . "%";

  $sql = ' SELECT gui_id, gui_nombre, gui_especialidad, gui_telefono, gui_direccion
           FROM guiaslocales
           WHERE gui_nombre LIKE :criterio';

  $q = $pdo->prepare($sql);
  $q->bindParam(":criterio", $criterio, PDO::PARAM_STR);
  $q->execute();
  $resultado = $q->fetchAll(PDO::FETCH_ASSOC);

In Frontend (VueJS)

await this.axios
      .post("guiaslocales.php?dato=getguias", JSON.stringify(parametros))
      .then(function (response) {
        if (response.status === 200) {
          self.guias = response.data;
          if (self.guias.length === 0) {
            self.mensajeWar("No se encontraron guias con ese criterio de busqueda");
          }
        }
      })
      .catch((error) => {
        this.global.catching(error);
      })
      .finally(() => {
        self.cargaskeletonguias = false;
      });

In PgAdmin work OK, but in PHP the SELECT LIKE that contains (ñ) or (´) returns empty