-3
HTML
<input type="checkbox" name="checkbox" value="Termos e Condicoes">
PHP
if(isset($_POST["checkbox"])){
echo "Checkbox Marcado";
...
// Cadastre o usuário
...
}else{
echo "Checkbox Desmarcado";
...
// Retorne para a página principal informando o erro
...
}
Note: In the image you posted the checkbox name is "chechbox", remember to receive $_POST["chechbox"] in php page... :)
Do not manifest code with images. It is difficult to read, you have to open in another tab on a desktop, a laptop has to leave the page and does not allow those who answer the question use [CTRL + C], [CTRL + V].
– Augusto Vasques