PICRUst 2 installation problem as a plugin for QIIME2-2021.2

I have installed QIIME 2-2021.2 vial virtualbox. The installation seems ok.
I ran"conda activate qiime2-2021.2"
then " conda install q2-picrust2=2021.2 -c conda-forge -c bioconda -c gavinmdouglas"

here is the error message I got,
qiime2-2021.2) [email protected]:~ conda activate qiime2-2021.2 (qiime2-2021.2) [email protected]:~ conda install q2-picrust2=2021.2 -c conda-forge -c bioconda -c gavinmdouglas
Collecting package metadata (current_repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.
Solving environment: