Does anyone know how to fix my problem here? It's just my action button is not showing, I am also not sure if I can input some matrix if it shows.

library(shiny) library(shinythemes) library(shinydashboard) library(shinyMatrix)

ui <- fluidPage(

navbarPage(title = "DETERMINANTS CALCULATOR", theme = shinytheme("sandstone"), tabPanel(value = "Home", icon("home"), fluidRow(column(width=12,height=20,

           tags$h1("Determinants", height = 4, style = "font-weight: bold; text-align; center;"),
           mainPanel(width = 3, height = 8, style = "border-style: solid; border-color: black;",
           br(),
           selectInput("matrix", "Choose a matrix dimension:", c("2", "3"),
           actionButton("set", "Set as Matrix"),
           ),
           ),
           ),
            mainPanel(
              uiOutput("matrixInput"),
              br(),
              actionButton("calculate", "Calculate"),
              tags$h3("Result of the Matrix", style = "font-weight: bold; text-align;center;"),
      )
      )               
      ),
         tabPanel(value = "About", icon("address-card"),
                  sidebarPanel(
                    h2("About the App", style = "font-weight: bold;"),
                    p("This web application complies with the final project or learning evidence to CS111, Advance Algebra for the first semester. This application can solve a 2x2 and 3x3 determinant matrix and multiply to row from echelon form to its diagonal element.", style = "font-weight:bold; text-center;")
  )
)

)
)

Sever matrix

server <- function(input, output) valueofdet = eventReactive(input$set, { matrix( nrow = input$matrix, ncol = input$matrix ) })

Run the application

shinyApp(ui = ui, server = server)

daattali / shinyalert

action button not popping off/showing in shinyapp #63

Sever matrix

Run the application