Unable to locate conda environment after creating it using .yml file

Question

I'm trying to create (and activate & use) a Conda environment using a .yml file (in fact, I'm following instructions on this GitHub page: https://github.com/RajLabMSSM/echolocatoR). I'm working in a cluster computing system running Linux.

conda env create -f https://github.com/RajLabMSSM/echolocatoR/raw/master/inst/conda/echoR.yml

After running the above line of code, I'm trying to activate the environment:

conda activate echoR

However, this returns the following message:

Could not find conda environment: echoR
You can list all discoverable environments with conda info --envs.

When checking the list of environments in .conda/environments.txt, the echoR environment is indeed not listed.

I'm hoping for some suggestions of what might be the issue here.