Hello @Beinn_Yule,
Your problem
This is the nature of iterator, It takes multiple elements(items) as an array and then processes them one by one. If you know computer programming then it’s the same as loop is used there.
Solution
Instead of the Iterator use the set multiple variable module then use the get() function to fetch the specific item from the array/collection.
After that use those variables in your api call.
To know more about how to use Get check this official Make Academy course.
https://academy.make.com/courses/IntermediateC02
P.S.: Always search first, Check Make Academy. If this is helpful, mark it as a solution 
and 
Need expert help or have questions? Contact or comment below! 