Betta Fish: Betta fish transformation 🫶🏻

I’m new to the hobby and this my first tank and the betta is my first fish. I just wanted to share his transformation!
First pic was taken March 28th and the second one was taken on May 11th.
He seems very happy in his 28L and I will soon be moving him (once it cycles) to a 36L long shallow tank since he struggles to get from one point to another (vertically) in my 28L tank 🫶🏻
Any tips / pointers / things to add to the new tank is deeply appreciated 🤍 I just want to give my betta the best life possible 🤍🤍