title: How to apply a class to a Shiny actionButton?
body: <p>I am using a bootstrap <a href="https://bootswatch.com/lumen/" rel="nofollow noreferrer">theme</a> for my application in shiny.</p>
  <p>This theme provides some button styles, which are associated with a certain class. For example:</p>
  <pre><code>&lt;button type=&quot;button&quot; class=&quot;btn btn-primary&quot;&gt;Primary&lt;/button&gt;
  &lt;button type=&quot;button&quot; class=&quot;btn btn-secondary&quot;&gt;Secondary&lt;/button&gt;
  &lt;button type=&quot;button&quot; class=&quot;btn btn-success&quot;&gt;Success&lt;/button&gt;
  &lt;button type=&quot;button&quot; class=&quot;btn btn-link&quot;&gt;Link&lt;/button&gt;
  </code></pre>
  <p>However, when I create a new button with:</p>
  <pre><code>shiny::actionButton(ns(&quot;btn_wuser&quot;),
                      class = &quot;btn btn-link&quot;,
                      label = &quot;Button&quot;)
  </code></pre>
  <p>I am unable to indicate which class the button should be linked to.
  I've tried also:</p>
  <pre><code>   shiny::actionButton(ns(&quot;btn_wuser&quot;),
                         style = &quot;class: 'btn btn-link;'&quot;)
  </code></pre>
  <p>Minimal reproducible example:</p>
  <pre><code>library(shiny)
  library(bslib)
  
  ui &lt;- navbarPage(
    theme = bslib::bs_theme_update(bslib::bs_theme(),
                        base_font = bslib::font_google(&quot;Montserrat&quot;),
                        code_font = bslib::font_google(&quot;Montserrat&quot;),
                        bootswatch = &quot;lumen&quot;,
                        bg = &quot;#ecf0f5&quot;,
                        fg = &quot;#000000&quot;),
     collapsible = TRUE,
  
     shiny::actionButton(&quot;btn_wuser&quot;,
                         class = &quot;btn btn-link&quot;,
                         label = &quot;Button&quot;
                         )
  )
  
  server &lt;- function(input, output, session) {
  }
  
  shinyApp(ui = ui, server = server)
  </code></pre>
  <p>Could someone help me?</p>