Korean language issue in Tex class

[desk14]

[manim version is 0.17.3, os: window10]

To use Korean in manim's Tex class
Enter the kotex package as \usepackage{kotex} in the tex_template.py file
and When I run t = Tex("안녕하세요"), I get the following error.
Of course the kotex package is installed in miktex.

[error message]
UnicodeDecodeError: 'cp949' codec can't decode byte 0x80 in position 2042:
illegal multibyte sequence
[32912] Execution returned code=1 in 8.182 seconds returned signal null

help me, please