I put all information, see my test code, what I'm doing wrong?
<html>
<body>
<form method="post" action="
https://podio.com/oauth/token?
grant_type=password&username=MY_USER&password=MY_PASS&client_id=teste-
int&redirect_uri=teste.html&client_secret=jQTbrbCF79J2CumBYd3BN233rKUpfo55fJCYjLCrNijGKaPg6RrTZfrwYz97FSzs"
id="frmPodio">
<input type="text" id="client_id" name="client_id" value="teste-int">
<input type="text" id="client_secret" name="client_secret"
value="jQTbrbCF79J2CumBYd3BN233rKUpfo55fJCYjLCrNijGKaPg6RrTZfrwYz97FSzs">
<input type="text" id="username" name="username" value="MY_USER">
<input type="text" id="password" name="password" value="MY_PASS">
<input type="text" id="redirect_uri" name="redirect_uri"
value="teste.html">
<input type="text" id="grant_type" name="grant_type" value="password">
<input type="button" onclick="frmPodio.submit();" value="Enviar">
</form>
</body>
</html>