I know that there are loads of similar questions posted but I just dont seem
to be able to figure this out.

I am trying to use
=SUMPRODUCT('order details'!$E$2:$E$1584=Summary!$E11,'order
details'!$B$2:$B$1584=Summary!G$6,'order details'!F2:F1584)

I highlighted range Summary!G11:Summary!G1573
Typed in the above
Pressed Ctrl + Shift + enter

What i want it to do in cell Summary!G11
On my order Details sheet I have an array where I want to pick out the value
from column F if Column E matches the value in Summary!E11 and Column B
matches the value in Summary!G$6.

I want the value Summary!E11to move down the page with the array formula but
Summary!G$6 will remain static

Any suggestions please