xyz

library(shiny)
library(shinythemes)

ui <- fluidPage(theme=shinytheme("cerulean"),
                navbarPage("Aplicaciones",
                           tabPanel("Nombre Completo"),
                           sidebarPanel(
                             tags$h3("Ingresa los siguientes datos:")),
                           textInput("primer_nombre","Primer Nombre:",""),
                           textInput("segundo_nombre","Segundo Nombre:",""),
                           textInput("apellido_paterno","Apellido Paterno:",""),
                           textInput("apellido_materno","Apellido Materno:",""),
                           mainPanel(
                             h1("Tu Nombre Completo es:"),
                             verbatimTextOutput("nombre_completo")),
                           
                           tabPanel("Tab 2"),
                           tabPanel("Tab 3"),
  ))

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

## Warning: Navigation containers expect a collection of
## `bslib::nav_panel()`/`shiny::tabPanel()`s and/or
## `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer`
## if you wish to place content above (or below) every panel's contents.

server <- function(input, output) {
  output$nombre_completo <- renderText(
    paste(input$primer_nombre,input$segundo_nombre,input$apellido_paterno,input$apellido_materno,sep = " "))
}
shinyApp(ui = ui, server = server)

Shiny applications not supported in static R Markdown documents