The description emphasizes easy DIY installation with included t-valve. Does that t-valve offer a back flow prevention feature or do I need to add a back flow prevention valve when I install the bidet?
What sort of backflow are you concerned about? It attaches to the water supply line to the tank.
I don’t have this exact model, but wanted to mention this… I have a similar bidet installed on a toilet in a bathroom that was an add-on to our house before we bought it. Because it was an add-on, there is no basement underneath it – just a sub-floor. If we have more than a few days of freezing temperature, the toilet line completely freezes.
BUT, with a bidet, I can open it up to a trickle and it keeps the pipes from freezing. While it’s not the intended use, it works great! Oh, and bidets are great in general. 
I’m in the US. When I googled about use and installation I saw that many plumbing codes overseas require a back flow preventer installed between the bidet and the water supply. An example is that most bidets as supplied are illegal in New Zealand because they don’t prevent back flow into the community water system. If the spray nozzle becomes submerged or is otherwise contaminated then contamination could be suctioned back into the water pipe. This got me thinking since I have a farmhouse that gets its water from a well.
You’ll need to add your own breaker valve then.