How do I plot a bivariate function equated to 0 in R and ggplot2?

I am trying to plot a bivariate function equated to 0 in R, using no packages other than the basic packages and ggplot2. Namely, the function is:

f(x,y) = x-log(x)+y-log(y)+C, where C < -2

Can I plot this function equated to 0, using R?. I did this using Desmos online graphing calculator and it worked, but now I can't figure out how to do it in R. I don't need the exact solution of x and y, but just the plot.