Connecction failure

I see following error while using Liquibase validate command:

Liquibase Version: 4.28.0

ERROR: Exception Details
ERROR: Exception Primary Class: NoSuchElementException

ERROR: Exception Primary Source: 4.28.0

Unexpected error running Liquibase: Connection could not be created to jdbc:db2://HOSTNAME with driver com.ibm.db2.jcc.DB2Driver. [jcc][10165][10045][4.33.31] Invalid database URL syntax: jdbc:db2://HOSTNAME. ERRORCODE=-4461, SQLSTATE=42815