plugins install
The plugins install
subcommand installs a Packer plugin at a version constraint
$ packer plugins install -hUsage: packer plugins install <plugin> [<version constraint>] This command will install the most recent compatible Packer plugin matching version constraint. When the version constraint is omitted, the most recent version will be installed. Ex: packer plugins install github.com/hashicorp/happycloud v1.2.3
Related
packer init
will install all required plugins.