I wanted to take some time and actually try to help you out. Rather than just say “you need RO” and bounce. So I put together a little shopping list for you. Feel free to modify for your needs.
RO filter (I run a 105L flower and a 68L veg res, and this produces more water than I need.)
https://www.amazon.com/gp/aw/d/B01M...+ro+system&dpPl=1&dpID=41WMui1PDfL&ref=plSrch
Resivor (You can use anything like this. I tried to find you one that is local for you. You could probably find a better deal. It took me a bit to find this one. I was searching the site for a “Garbage or Trash can” and nothing was coming up in the results. Then I learned you call them “Bins / Big wheelie bins” on the other side of the pond. Popped right up.
https://www.diy.com/departments/black-wheelie-bin/1892858_BQ.prd
Y splitter for the water supply.
https://www.amazon.com/gp/aw/d/B018...tter+2+way&dpPl=1&dpID=51rWZ-DI2mL&ref=plSrch
Float valve. Not a necessity, but makes life easier for so little money. Turns the water flow on and off automatically. So you don’t forget to turn it off and it floods, or forget to turn it on and it’s almost empty when you need it. If you change the filter, make sure it has the cut off block. Otherwise there is a float that has the block included for a few bucks more. If you don’t have the shut off block, the valve will close the product water off, but everything will continue to run out the drain tube.
https://www.amazon.com/gp/aw/d/B007...loat+valve&dpPl=1&dpID=21IEvJlhdgL&ref=plSrch
And if you really want to get high speed, a small transfer pump, on/off switch and some hose.
https://www.amazon.com/gp/aw/d/B01E...0+gph+pump&dpPl=1&dpID=419ctYNFTYL&ref=plSrch
Something like this but for your outlets.
Cheap hose
That should get you up and running. If you get everything on the list it’s basically set it up and forget it, with RO water on demand.