How to use 2 Tabs at the Same time

[Skrylor]

The website is opening another window and with the 1st window he is checking if the 2 one is loaded and then he starts a timer from 5 sec, i tried multiple ways but the checking system is not working on the 1. Tab.

This is how the Timer looks like

Then i Need to Press this button

And after 5 Secounds in the new Window it goes to this

I Tried Multiple ways but couldnt figure out how to make it work

[Skrylor]

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