Use the pip install command to install pyvault. I like to go with version 1.9 because starting with version 2.x sqlcipher is required and I find it much easier to go with 1.9 to avoid issues with the sqlcipher package.

pip install pyvault==1.9

Then issue the vault command and the following should be displayed. When prompted for your master key, enter a password that will be used as the master key (password) for the vault.

~]$ vault
    __      __         _ _           .----.    
    \ \    / /        | | |         / /  \ \   
     \ \  / /_ _ _   _| | |_       _| |__| |_  
      \ \/ / _` | | | | | __|    .' |_   |_| '.
       \  / (_| | |_| | | |_     '.__________.'
        \/ \__,_|\__,_|_|\__|    |            |
                                 '.__________.'
Welcome to Vault. Please choose a secure secret key.

🔑  Please choose a master key:

If your password / master key is accepted, something like this should be displayed.

🔑  Please choose a master key:
🔑  Please confirm your master key:

Your vault has been created and encrypted with your master key.
Your unique salt is: 798a8980-6a1b-466a-9088-90d5faaff2f3 
Write it down. If you lose your config file you will need it to unlock your vault.

🔑  Please enter your master key:

Choose a command [(s)earch / show (all) / (a)dd / (cat)egories / (l)ock / (q)uit]: