botman command not found in ubuntu

Dear All
i am try to start to learn botman , when i follow the installation step for botman studio , after success install the botman studio using this command "composer global require "botman/installer". i can't to do next step because the botman command not found in system. for installation process , i have not found any error occur , the log below:
Changed current directory to /home/pi/.config/composer
Using version ^1.0 for botman/installer
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
- Installing botman/installer (1.0.4): Downloading (100%)
Writing lock file
Generating autoload files

Any idea on it? Thanks!