Clone the package to your system:
git clone https://github.com/ucsdarclab/pybullet-gym-env.git
install it using pip:
pip install -e pybullet-gym-env/
Once the package is installed, you can create an environment using the following command:
env = gym.make("modified_gym_env:ReacherPyBulletEnv-v1", rand_init=False)
If rand_init=True, then the arm will initialize to a random location after each reset.