Error installation conda busco 4.0.5

I had the same issue as #179 (closed) : What I have done so far (on a cluster with centos) :

conda install -c bioconda -c conda-forge busco=4.0.5

conda activate base

But when i try busco -h

No module named 'busco' There was a problem installing BUSCO or importing one of its dependencies. See the user guide and the GitLab issue board (https://gitlab.com/ezlab/busco/issues) if you need further assistance.

Thanks for your help

Alexis