Error: could not find a Python environment for /usr/bin/python3

I am trying to use the reticulate() package in R to run some Python packages.

I run the following:

library(reticulate)
py_install("pandas")

I obtain this error:

Error: could not find a Python environment for /usr/bin/python3

Running py_config() gives:

python:         /usr/bin/python3
libpython:      /usr/lib/python3.6/config-3.6m-x86_64-linux-gnu/libpython3.6.so
pythonhome:     //usr://usr
version:        3.6.9 (default, Nov  7 2019, 10:44:02)  [GCC 8.3.0]
numpy:          /home/user/.local/lib/python3.6/site-packages/numpy
numpy_version:  1.18.1
tensorflow:     /home/user/.local/lib/python3.6/site-packages/tensorflow

python versions found: 
 /home/user/.virtualenvs/r-reticulate/bin/python
 /usr/bin/python3
 /usr/bin/python
 /home/user/anaconda3/bin/python
 /home/user/env/bin/python
 /home/user/miniconda3/bin/python

When I navigate to /usr/bin/ there is a file called python3.7 and there is a folder called python3but when I try to open it I get the following error Directory /usr/bin/python3.6: no such file or directory. I cannot open or access the python3 folder (or any folder) in the /usr/bin/ directory.

I also run

use_python("/home/user/miniconda3/lib/python3.7/") 
py_install("pandas")

Which gives me the same error.

I am running an AWS Ubuntu instance with RStudio installed.