Getting an error "pytest: command not found" while running a Selenium-Python test from CircleCI

I am trying to learn CircleCI as we have a client requirement to use the same. I am trying to run my Selenium project code written in Python language but getting pytest: command not found error. I have mentioned the PyTest installation in my requirement.txt file, I also tried to install the PyTest by running the below command but still got the same error.

Here is my config.yml file

version: 2.1

orbs:
  python: circleci/python@2.0.3


jobs:
  example-job:

    
    docker:
    - image: circleci/python:3.6.1

    
    steps:
      - checkout
      - run: pip install pytest --user
      - python/install-packages:
          args: pytest --user
          pkg-manager: pip
          pypi-cache: false
      - run: 
          command:
            pytest businessObjects/test_Login.py


workflows:
    example-workflow:
      jobs:
        - example-job

Error is

#!/bin/bash -eo pipefail
pytest businessObjects/test_Login.py
/bin/bash: pytest: command not found

Exited with code exit status 127
CircleCI received exit code 127