so that you can use the later versions of Flash.
OS X 10.3.9 is so far back that the Flash player that you have installed is not capable of reading the current levels of Flash and I'm a little surprised that your iBook G4 is still functioning after all this time. They were not the best of models that Apple released.

Your machine can support at least 10.4.11, which is still old but not as old as your current version.

It will also be expensive as you will have to troll ebay or Amazon to find a copy for your computer.

The other solution is to get a new computer, not always an option

P