take input and add in dropdown code example

Example 1: html form select

<!-- O segundo valor estará selecionado inicialmente -->
<select name="select">
  <option value="valor1">Valor 1</option> 
  <option value="valor2" selected>Valor 2</option>
  <option value="valor3">Valor 3</option>
</select>

Example 2: textbox dropdown with manual input

<label>Choose a browser from this list:
<input list="browsers" name="myBrowser" /></label>
<datalist id="browsers">
  <option value="Chrome">
  <option value="Firefox">
  <option value="Internet Explorer">
  <option value="Opera">
  <option value="Safari">
  <option value="Microsoft Edge">
</datalist>