Bemob - double meta?

[idohorizontech]

Hello,

So I am about to run my first campaign.. YAYYY..
I will create a follow along once I'll launch

I added my offer (sweeps iphone 11 pro)
I added my lander
I added postback in the network(starting with Golden goose - their affiliate manager was the nicest and helped a lot).
I added my traffice source (Zeropark)

Now I want to create a flow in bemob:

do I use double meta? if so, on both lander and offer?
what does double meta mean?

Then I am going to run my campaign... so cool...

Thanks for your