Most likely no chemical drain cleaner will work. They generally work to loosen house hold kitchen sink blockage that are mainly caused by grease and harden soaps. In part they generate heat and you'll be diluting the chemical in a lot of water.
Your blockage is from roots, leaf debris or just plain sand and dirt. Do you know where the other end is? Sometimes they'll go to a sump pump or drain further away from the home with just an open pipe. The end opening could be causing the block. You can start with a garden hose with a jet nozzle and with a wide open spigot. Push the hose as far as you can. If there are any 90 degree bends it won't go any further. Sometimes one drain basin goes to another basin and the block could be further down the line. I have a few basins in my yard. I have a jetter that attaches to my pressure washer and I've cleared a few drains with it.
A good handyman (if that is a trade in Au) should be able to take care of this.