How do I call a function into another file?

I have a function in a file called kguess.m that has this and produces the value for k

function k = kguess(w, g, h)
 k = (w) / (g*sqrt(tanh((w)*h)/g)); 
end

But I am trying to use the ouput from the file kguess.m and plug it into equations within another file called my_function.m and I am not sure why I am getting errors. I have tried different methods but none seem to work. Could someone please help me?

g = 9.81;
H = input('Input a value for the variable H: ');
Ws = input('Input a value for the variable Ws: '); 

k = [k]; 
for n = k:100
F = g.*k.*tanh(k.*H)-Ws;
FP = g.*(tanh(k.*H))+k.*(sech(k.*H).^2);


    A = k - (F/FP);
    
    k = k +1;
end 

[Walter Roberson]

k = kguess(Ws, g, H);