PyInstaller Eel : TypeError: an integer is required (got type bytes)

I am getting this error when I try to build (package) my Eel program using pyinstaller. Please help me I am using Python 3.8.1

C:\Users\admin\Desktop\project>python -m eel script.py web
Building executable with main script 'script.py' and web folder 'web'...

Running:
pyinstaller script.py --hidden-import bottle_websocket --add-data C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\eel\eel.js;eel --add-data web;web

603 INFO: PyInstaller: 3.5
604 INFO: Python: 3.8.1
605 INFO: Platform: Windows-10-10.0.18362-SP0
607 INFO: wrote C:\Users\admin\Desktop\project\script.spec
611 INFO: UPX is not available.
614 INFO: Extending PYTHONPATH with paths
['C:\\Users\\admin\\Desktop\\project',
 'C:\\Users\\admin\\Desktop\\project']
614 INFO: checking Analysis
877 INFO: Appending 'datas' from .spec
882 INFO: checking PYZ
883 INFO: Building PYZ because PYZ-00.toc is non existent
883 INFO: Building PYZ (ZlibArchive) C:\Users\admin\Desktop\project\build\script\PYZ-00.pyz
Traceback (most recent call last):
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\runpy.py", line 193, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\eel\__main__.py", line 24, in <module>
    pyi.run(full_args)
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\__main__.py", line 111, in run
    run_build(pyi_config, spec_file, **vars(args))
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\__main__.py", line 63, in run_build
    PyInstaller.building.build_main.main(pyi_config, spec_file, **kwargs)
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\build_main.py", line 844, in main
    build(specfile, kw.get('distpath'), kw.get('workpath'), kw.get('clean_build'))
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\build_main.py", line 791, in build
    exec(code, spec_namespace)
  File "C:\Users\admin\Desktop\project\script.spec", line 18, in <module>
    pyz = PYZ(a.pure, a.zipped_data,
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\api.py", line 98, in __init__
    self.__postinit__()
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\datastruct.py", line 158, in __postinit__
    self.assemble()
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\api.py", line 128, in assemble
    self.code_dict = {
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\api.py", line 129, in <dictcomp>
    key: strip_paths_in_code(code)
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\utils.py", line 652, in strip_paths_in_code
    consts = tuple(
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\utils.py", line 653, in <genexpr>
    strip_paths_in_code(const_co, new_filename)
  File "C:\Users\admin\AppData\Local\Programs\Python\Python38-32\lib\site-packages\PyInstaller\building\utils.py", line 660, in strip_paths_in_code
    return code_func(co.co_argcount, co.co_kwonlyargcount, co.co_nlocals, co.co_stacksize,
TypeError: an integer is required (got type bytes)