Dynamic field update after API call

Hey Bubble community,

I’m still a bit stuck on trying to get this to work. Basically I have set up an API which is connected to a model.

Essentially what I’m trying to achieve is to adjust the input values, make a call to the external source and for it to return a corresponding output value.

In this case the input would be Sum Assured vs the output which is Annual Premium.

I’m still confused as to how I can get this to work… have tried using both ‘Data’ and ‘Action’.

Appreciate any help!