https://www.ibm.com/docs/en/db2/11.5.x?topic=commands-db2cmd-open-db2-command-window
db2cmd - Open Db2 command window command
Opens the CLP-enabled Db2 window, and initializes the Db2 command line environment. Issuing this command is equivalent to clicking the Db2 Command Window icon.
opencommandwindow