remotes::install_github("ggobi/ggally#300")

library(ggplot2)
#> Registered S3 methods overwritten by 'ggplot2':
#>   method         from 
#>   [.quosures     rlang
#>   c.quosures     rlang
#>   print.quosures rlang
library(GGally)
#> Registered S3 method overwritten by 'GGally':
#>   method from   
#>   +.gg   ggplot2

ggpairs(
  iris, 
  1:3, 
  upper = list(
    continuous = function(data, mapping, ...) { 
      ggplot(data, mapping) + 
      geom_point() + 
      scale_x_continuous(sec.axis = sec_axis(~.+10)) + 
      scale_y_continuous(sec.axis = sec_axis(~.+10))
    } 
  ) 
) + 
  theme(strip.placement = "outside")