How can I install gekko package using R reticulate?

Question

I can't install gekko package via R reticulate. My R version is 3.4.4 and my Python version is 3.8.8 and I use Gekko in Python without problems. So I tried to install on R in these two ways I know:

1. py_install("gekko")

2. reticulate::conda_install("my_conda_environment", "gekko")

However in both cases I receive the same error bellow.

PackagesNotFoundError: The following packages are not available from current channels:

• gekko

Current channels:

• https://conda.anaconda.org/root/win-64
• https://conda.anaconda.org/root/noarch
• https://repo.anaconda.com/pkgs/main/win-64
• https://repo.anaconda.com/pkgs/main/noarch
• https://repo.anaconda.com/pkgs/r/win-64
• https://repo.anaconda.com/pkgs/r/noarch
• https://repo.anaconda.com/pkgs/msys2/win-64
• https://repo.anaconda.com/pkgs/msys2/noarch

I didn't find other alternatives in the Anaconda documentation. How can I fix this?

Edit: I solved my problem based on the references in John Hedengren's answer and reticulate docs. For that, I needed to create a new environment to specify the Python version and packages using the following code in R:

reticulate::py_install(
    packages = c(
        "numpy",  
        "pandas", # Or another packages that you need
        "gekko"
    ),
    envname  = "r-gekko",
    method = "conda", # On Windows, the 'conda' method is always used
    python_version = "3.8.8",
    pip = TRUE # It's mandatory to install gekko
)

Answer 1

A more general answer for help in similar cases:

1. Install gekko and other packages in a new environment in R.

reticulate::py_install(
    packages = c(
        "gekko",
        "other_package==x.x.x", # It's possible to specify the package version 
        ... 
    ),
    envname = "new_env",
    method = "conda", # For Windows
    python_version = "3.x.x",
    pip = TRUE
)

2. Call reticulate package using the new environment.

Sys.setenv(RETICULATE_PYTHON = "/Users/user_name/anaconda#/envs/new_env/python.exe")
library(reticulate)

3. Run your Python script with gekko in R.

source_python("path/script.py")