How do I remove all variable names and leave values only in my export in R?

Question

I have this code:

library(openxlsx)
library(tidyverse)

rid <- (c(1:20,NA))
RISN <- (c(1:20, NA))
Fake <- (c(1:20, NA))

df <- tibble(rid, RISN, Fake)

df <- df %>% filter(!is.na(rid) & !is.na(RISN)) %>% select(RISN,rid)

write.xlsx(df, "~/Downloads/df_test.xlsx", asTable = FALSE)

I need my export to appear like this with the "rid" and "RISN" column names removed. I'm not sure if this is possible. Does anyone know a way around this? I suspect I need to convert it from a tibble type to something else, but I've tried matrix and it's not working for me.