How to plot this step-wise function?

See the FAQ: How to do a minimal reproducible example reprex for beginners.

If

eq <- function(x) dplyr::case_when(
  x <= -0.05 ~ 0,
  x > 0.05 & x <= 0.95 ~ x + 0.05,
  x > 0.95 ~ 1
  )

isn't what you intended, provide a replacement.