Thanks to those that provided me with helpful feedback on why my few day old betta was struggling.
I have rehabbed him in a hospital tank, plus made lots of changes to the tank (as well as ensuring all the parameters are correct).
Today he’s gone back into the tank and has been having a great time exploring his new home 💙
https://www.reddit.com/gallery/1s28bez
Posted by Distinct_Affect3355