Create a text box and write in a pdf

Code to display the pdf document:

$result_cursos = "SELECT * FROM centrodb.UploadPDF";
$resultado_cursos = mysqli_query($conn, $result_cursos);    
$tabela1 .= '<div class="teste" id="tabela" style="float: center" table align="center">';   
$tabela1 .= '<table align="center"  height="100%" border="5" id="tabela">';
$tabela1 .= '<tr>';
$tabela1 .='<thead>';
$tabela1 .= '<tr>';
$tabela1 .= '<th style="width:80px">Ementas</th>';
$tabela1 .= '</tr>';
$tabela1 .='</thead>'; 
$tabela1 .='<tbody>';
while($rows_cursos = mysqli_fetch_array($resultado_cursos)) {   
$tabela1 .= '<tr>';
$tabela1 .= '<td><iframe src="/wordpress/wp-content/themes/busiprof/Upload/' .$rows_cursos['txtArquivo']. '" width="600" height="780" style="border: none;" ></iframe></td>';
$tabela1 .= '</tr>'; }
$tabela1 .= '</tr>';
$tabela1 .='</tbody>'; 
$tabela1 .= '</table>';
$tabela1 .= '</div>';
echo $tabela1;

After opening the pdf, I wanted to be able to create a text box so that I could write to the pdf and save those changes with the text box in the database table. Is it possible to do this?