Why won't the Thailandplus app open before entering Thailand for the Phuket Sandbox?

The user cannot open the Thailandplus app on their phone while in the UK and questions if this is normal or if it's due to low storage. Several comments indicate that the Thailandplus app is outdated and users should download the Morchana app instead. It's suggested that once the user arrives at the airport in Thailand, they will receive assistance in connecting to Wi-Fi and using the new app. Some users also report issues with downloading the Morchana app and mention that it may only work for those vaccinated in Thailand.