404 NOT FOUND jupyter notebook

I am facing the same problem again . I do not know how to close current notebook in cloud x lab . So I cut the cells after downloading the file and rename.
I think my file get closed because of this

You can follow jupyter documentation on the same.

Sir
I tried installing jupyter using pip install jupyter but it did not work.
I also tried using export PATH=/usr/local/anaconda/bin :$PATH
python3
That also did not work.
I am currently working on jupyter but it doesn’t open in playground, it opens in another tab and while submitting my answers for numpy I faced different problems
Please write the steps for removing 404 error I will follow the steps.

After trying installation etc(all failed unfortunately) today I created a file named python and the notebook appeared in my playground.
Problem solved