To overcome the error, we have to manually add the service name into the listener. So that listener starts to detect the database services.

Open the listener.ora file at ORACLE_HOME\network folder. In the following example, no services seem to be registered in the listener.ora file

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\Oracle\dbhomeXE)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:C:\Oracle\dbhomeXE\bin\oraclr18.dll")
    )
     )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )

Add the following line to manually register the PDB1 database service in the listener.ora file:

(SID_DESC =
	(GLOBAL_DBNAME = PDB1)
	(ORACLE_HOME = C:\Oracle\dbhomeXE)
	(SID_NAME = PDB1)
	)

Now the final listener file becomes:

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\Oracle\dbhomeXE)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:C:\Oracle\dbhomeXE\bin\oraclr18.dll")
    )
	(SID_DESC =
	(GLOBAL_DBNAME = PDB1)
	(ORACLE_HOME = C:\Oracle\dbhomeXE)
	(SID_NAME = PDB1)
	)
     )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )