Can't install pip3 for python 3.9

I've tried everything, I've tried doing the following:

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py python3.9 get-pip.py

But that just gives me the following error:

root@ubuntu18:~# python3.9 get-pip.py
Traceback (most recent call last):
  File "/root/get-pip.py", line 24184, in <module>
    main()
  File "/root/get-pip.py", line 139, in main
    bootstrap(tmpdir=tmpdir)
  File "/root/get-pip.py", line 120, in bootstrap
    args = determine_pip_install_arguments()
  File "/root/get-pip.py", line 65, in determine_pip_install_arguments
    import setuptools  # noqa
  File "/usr/lib/python3/dist-packages/setuptools/__init__.py", line 14, in <module>
    from setuptools.dist import Distribution, Feature
  File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 24, in <module>
    from setuptools.depends import Require
  File "/usr/lib/python3/dist-packages/setuptools/depends.py", line 7, in <module>
    from .py33compat import Bytecode
  File "/usr/lib/python3/dist-packages/setuptools/py33compat.py", line 54, in <module>
    unescape = getattr(html, 'unescape', html_parser.HTMLParser().unescape)
AttributeError: 'HTMLParser' object has no attribute 'unescape'

And i've sat hours trying different fixes, when i do pip3 --version it shows that its using python 3.6

And your thinking, why do i need to install it for python 3.9, well the py app im using only supports that and when i try to run it using python3.9 app.py it says that there is missing pip3 modules even though its installed.

I hope someone can tell me a fix, or what's causing the error.

Thanks.