Using the mui framework, how to set up app to run in the background for a long time

1 the mui development app, program used to run in the background for a period of time will be killed by the mobile phone. When it comes to app, it has a live chat function. The problem of running in the background must be resolved.
2 does mui, currently have no solution to this problem? Or to solve this problem, you must develop app in the native language.
3 how does an application like Wechat QQ not be killed by a mobile phone? even if you clear the background program and click on the app again, it will be awakened directly without having to load the initial page.

I hope you can give me some help. I feel overwhelmed.

Mar.22,2021

even native app has no way to stop the memory management mechanism of the system. So it's inexplicable. You can only set manually to allow app to start automatically.

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