Use character vector in subtitle of ggplot

tidyverse
2

Is this what you mean?

library(ggplot2)

text <- "Any text you want"

ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width)) +
    geom_point() +
    labs(title = "Some Title",
         subtitle = text)

Created on 2020-03-06 by the reprex package (v0.3.0.9001)

If this is not what you want, please provide a proper REPRoducible EXample (reprex) illustrating your issue.