How to keep ios app running in background?

I have an Ionic app that run some tasks periodically (say every hour).

On android works fine. However, on ios, when app is in background, tasks are not done until app resume.

Is there a way to keep ios app running?

Local notifications are not a solution because it needs user action.
I installed cordova-plugin-background-fetch, but it is not exactly what I want because background-fetch execution is quite random.
I also read that ios suspends app works about 3 minutes after going to background.

Any help will be appreciated.