GGplot2 plotting fitted lines

Hi amazing Rstudio community

I'm having a problem with ggplot2 and the fitted lines
I want to have a sharp fitted line line you can get with the standard plot function in R. However, my ggplot2 won't allow this and it only gives a smooth fitted line. Please see the one graph (which shows the line that I want - but on ggplot2 and not the standard R package) and if anyone can help me, I would really appreciate it.

Thank you.

Hi!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one: