调用一个函数在c中的另一个函数调用中返回一个字符串

I am currently working on a program with the Dante Brooklyn II board from audinate. I am trying to use a void return function from the Dante API - foo() - that needs to have 3 various structs passed in as well as 2 strings. I have another function get_value_by_key() which returns the string value that I need. I initially tried calling on the program like so:I am currently working on a program with the Da