How to use two objects in a single row in FlexDashboard?

Question

I have a column with a chart in FlexDashboard. I would like to put a download button under the chart, but it's showing just the top of the buttom.

My code:

renderPlotly({
      ggplotly(
            juros %>% 
                  filter(data %in% as.Date(input$datas_juros),
                         tipo == input$tipo_juros) %>%
                  ggplot(aes(x = anos, y = valor, color = as.factor(data))) + 
                  geom_line() +
                  geom_point() +
                  labs(y = "(%)", x = "Anos", color = "", 
                       title = "Estrutura a Termo da Taxa de Juros") +
                  scale_x_continuous(breaks = seq(0.5, 10.5, 0.5)) +
                  scale_color_manual(values = unname(colors)) +
                  theme(panel.background   = element_rect(fill = "white", colour = "white"),
                        axis.line          = element_line(colour = "black", linetype = "dashed"),
                        axis.line.x.bottom = element_line(colour = "black"),
                        panel.grid.major   = element_blank(),
                        plot.title         = element_text(size = 12, face = "bold"),
                        panel.grid.minor   = element_blank(),
                        plot.margin = margin(5, 5, 15, 5))
            ) %>%
            config(displayModeBar = FALSE) %>%
            style(hoverinfo = "y")
  })

renderUI({
      juros %>% 
            filter(data %in% as.Date(input$datas_juros),
                   tipo == input$tipo_juros) %>%
            select(-c(tipo, data)) %>%
            download_this(
                  output_name = paste("ETTJ -", input$tipo_juros),
                  output_extension = ".xlsx",
                  button_label = "Download do arquivo em Excel",
                  button_type = "success",
                  has_icon = TRUE,
                  icon = "fa fa-save")
})

My output:

This green bar is my download button. If I click there, I can download the data, but how can I move this button to show it completely?