R shiny: update of random variable depending on action button [duplicate]

This is a minimal work example of a larger application in R shiny that I'm working on at the moment. Each time I click the actionbutton "OK" I want to generate a new randam variable between 1 and 3 and display it. I get the following error message: Shiny app fails with “argument 1 (type 'closure') cannot be handled by 'cat'” - what does this mean?

ui <- fluidPage(
    
    titlePanel("Random Veriable"),
    actionButton("ok", "OK"),
    br(),
    verbatimTextOutput("anubis")
)

server <- function(input, output) {
    
    anu <- eventReactive(input$ok,{
        
        sample(c(1:3), size = 1, replace = T)
    })
    
    output$anubis <- renderText({
      
        if(input$ok > 0)
        {
            anu
        }
        
        else{
            0
        }
        
   })
}

I'd be happy if someone could show me where I went wrong in defining my variable anu.