"duals" should be "dual" below (from p. 21 of the documentation):

## Not run:
library(magrittr)
result <- MIPModel() %>%
add_variable(x[i], i = 1:5) %>%
add_variable(y[i, j], i = 1:5, j = 1:5) %>%
add_constraint(x[i] >= 1, i = 1:5) %>%
set_bounds(x[i], lb = 3, i = 1:3) %>%
set_objective(0) %>%
solve_model(with_ROI("glpk"))
solution <- get_solution(result, x[i])
solution2 <- get_s