Django報錯TypeError join() argument must be str or bytes, not 'dict'如何解決？

如題，在調試Django時報錯，不知哪里出了問題，求大佬解答！！！

class MobileModelForm(forms.ModelForm):
    # Exception Value: join() argument must be str, bytes, or os.PathLike object, not 'dict'
    mobile = forms.CharField(
        label='手機號',
        validators=[RegexValidator(regex=r"^1[3-9]\d{9}$", message="手機號碼格式錯誤"),]
    )
    class Meta:
        model = models.PrettyNum
        fields = ["mobile","price","level","status"]
        # fields = "__all__"  # 所有字段
        # exclude = ["level"]  # 排除哪些字段
    def __init__(self,*args,**kwargs):
        super().__init__(*args,**kwargs)
        for name,field in self.fields.items():
            field.widget.attrs = {"class":"form-control"}

添加了validators=[RegexValidator(regex=r"^1[3-9]\d{9}$", message="手機號碼格式錯誤"),]這句話就報錯，懵了
TypeError
Exception Value:
join() argument must be str or bytes, not 'dict'

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我知道我哪里錯了，忘記寫request了