On Ubuntu
First download the latest version of Miniconda3 and run it to install.
wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh
sh Miniconda3-latest-Linux-x86_64.sh
Follow the instructions on screen replying yes
when necessary. Restart your terminal window to apply modifications. After restarting, you can type the command below to install Mamba:
conda init
conda install -n base -c conda-forge mamba