HTH
Let me know if I can be of any further assistance
Steve

Part II
Here are some links to get you started:

www.amazon.com/gp/product/B000EXWIVM/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1

www.amazon.com/PERA-assembly-liquid-disconnect-brewing/dp/B079LX9575/ref=sr_1_20?crid=1QKJBA0T4EHDR&dchild=1&keywords=c arbonation+cap&qid=1598914515&sprefix=carbonation% 2Caps%2C187&sr=8-20

www.amazon.com/gp/product/B01K4GGYT0/ref=ppx_od_dt_b_asin_title_s02?ie=UTF8&psc=1

As I said, it is very simple. We also use th CO2 to preserve sealed containers with things like flour, etc in them.
You will find that it is a lot easier to just buy the soda as you go along, but this is fantastic for making fresh sodas from fruit, etc. You can also have sodawater whenever you wish.

Part I
Hi Mark
Sorry. I missed your message. Sure, what do you want to know?

It is really quite simple:

You need:
A bottle of CO2
A regulator
Hose
A carbonating head
An adpator to fit the bottle

To use:
Fill your bottle with water and flavour
Chill as cold as you can get it (this very significantly improves the speed and depth of carbonation achieved - even the bottlers use it, I am told)
Squeze the bottle to expel all the air from the top and apply the carbonation cap.
Connect to the carbonating head.
Open the tank and set your pressure.
SHAKE the bottle as it fills.

Hi,
Was looking at the DIY soda stream thread where tou offered the OP more info on how to do it. Would you please share that with me as well?
Thanks,
Mark