https://www.ibm.com/docs/en/db2/12.1.x?topic=commands-db2nrupgrade-upgrade-non-root-instance
db2nrupgrade - Upgrade non-root instance command
Upgrades a non-root instance from a previous version of the Db2 database system to the current version of the Db2 copy from where you are running the...
upgradenonrootinstancecommand