Assign the escape key to exit an optin. ikhc6rkql15ly9mx = optin's slug
$(document).keyup(function(e) {
if (e.keyCode == 27) { // escape key maps to keycode `27`
if( typeof window.ikhc6rkql15ly9mx !=='undefined') {
window.ikhc6rkql15ly9mx.close(true);
}
}
});