导出highchart到图像阿拉伯文本

Question

am尝试将highchart导出为图像，导出图表的阿拉伯文标签显示为问号后，我的高级图表包含阿拉伯标签（标题），我尝试添加（useHTML）并将脚本编码更改为（utf8），但仍显示为问号。

class Vote(models.Model):
    title = models.CharField(max_length = 50, blank=False)
    start_date = models.DateTimeField(blank=False)
    end_date = models.DateTimeField(blank=False)
    votes_to_win = models.IntegerField(blank=False)

class Character(models.Model):
    name = models.CharField(max_length=20)
    image = models.ImageField(upload_to='img')
    age = models.IntegerField()
    vote = models.ManyToManyField(Vote, through='VoteForCharacter')

class VoteForCharacter(models.Model):
    vote = models.ForeignKey(Vote, on_delete=models.CASCADE)
    character = models.ForeignKey(Character, on_delete=models.CASCADE)
    votes_number = models.IntegerField(default=0)
    class Meta:
        unique_together = ('vote', 'character',)

导出时显示如下