WP GA plugin.Which tracking method?Global site tag

I have GA Google Analytics plugin in WPress

Here i have put the Global site tag taken from GA

In the settings for GA tracking, how do we know which setting to use in the “tracking method” section?

I have a UA code at the top under GA tracking ID.

But my web person has also just put into the source code somewhere a GA Global site tag.
The “tracking method” turned on at the moment here is for Universal Analytics ( analyticsjs )default.

But should it be Global site tag ( new method )

also, do i need this code at all if i already am connected to SC with a meta tag from Yoast plugin?

Thanks for any advice