How to Append a new line in executed command without rewriting whole again in Oracle Sql plus

this video shows how to add a new command statement in the last executed set of command statements and run all of them as once writing the executed command again.
So if we just ran 3 line statement and now want to run same with another statement in it then we don't need to rewrite because they are in buffer and we just append one new line and run it by front slash /.