PIR3-RF. "Two Modes, As You Choose". How I choose?

The manual says “PIR3-RF has two built-in modes which are two different trigger time mechanisms to meet your needs in different scenarios”.
I’m using eWeLink app.
My question is, how do I choose the mode?
Thank you.

@Daniel_Zhan loops daniel from SONOFF team.

Please check the user manual from official SONOFF site.

I was ofuscated.