Plotting single points on an anonymous function

I have a function which depends on a single variable x and a variable l.
I plot these functions for different integer variables of l like so:
plot!(fig, x->f(x, l=3))

so in general:

plot!(fig, x->f(x, l=i))

However for each f(x,i), there is a specific point on the curve that I want to label depending only on x-values that i have, ideally like this (the following is pseudocode):

plot!(fig, x->f(x, l=3), label(f(some_number), red, sploosh, 5pt))

Is this possible or do I really need to create a separate dataframe, calculate the x- and y values and overlay the plot with a scatter based on those values?


 annotate!(x0, f(x0, l=3), text("sploosh", :red, 5))

Thank you very much!

A small follow-up question, how can I mark the actual point on the graph, rather than floating something besides it with annotate!() ? I have searched for it the past 3 hours but I can’t seem the find a function that ploints a simple single point without using convoluted ways with scatter and whatnot.
Thanks in advance!

scatter!([x0], [f(x0, l=3)])

Thank you!