Install.sh issue

This is the error i receive, although I have pip and python3 installed:
install.sh: 27: pushd: not found
Installing InstaPy...
sudo: pip: command not found
install.sh: 32: pushd: not found
Setup is completed.
Press any key to continue...
When I press some keys it just writes them, and if I press enter it returns to the "Linux" folder(I'm using Debian)

Start with install.sh, especially lines 27 and 32, and reproduce the script on Debian using the reported Python and pip setup. Check why pushd and pip are unavailable in that shell, and verify the script's final prompt and return behavior. Done means the installation completes without the reported command errors and the prompt behaves as expected.

Written by the indexing model from the issue text.