I’d use a spin pipe rather than a lily re BettaAlto, would you use an external filter for this type of tank with lily pipes? Just don’t want the flow causing problems for the Betta. Ideally I’d add a kuhli loach, some amanos, Otocinclus and maybe a shoaling fish to keep the Beta active.
Also, what lighting? Twinstar 600S? Won’t have CO2 so I’d choose easy care plants.