Visa requirements as a Swede; Melbourne - Haikou, Haikou - Changsha - London

My partner is Swedish and we will be travelling via China for less than 24 hours using Hainan Airlines for the following flights.

Flight HU484
Melbourne Haikou
MEL - Melbourne Airport HAK - Haikou Meilan International Airport
Terminal TERMINAL 2 Terminal TERMINAL 2
8:45 PM - Sunday, 22 December 2024 3:30 AM - Monday, 23 December 2024

Flight HU7963
Haikou London
HAK - Haikou Meilan International Airport LHR - London Heathrow Airport
Terminal TERMINAL 2 Terminal TERMINAL 3
8:00 AM - Monday, 23 December 2024 5:55 PM - Monday, 23 December 2024
(This flight includes a stopover in Changsha, China for 3h 45m)

Can someone please confirm if you can apply for an entry permit on arrival, noting we are in China for less than 24 hours?