A token can be parsed from a string and transformed into a LittleApps\LittleJWT\JWT\JWT instance. If the token cannot be parsed, parseToken() will return null. This means the token could not be parsed, not that it couldn't be validated. More information the JWT instance can be found in The JWT documentation.
use LittleApps\LittleJWT\Facades\LittleJWT;
$token = "...";
$jwt = LittleJWT::parseToken($token);
if (! is_null($jwt)) {
// The JWT was parsed.
// This does NOT mean the JWT is valid.
} else {
// The JWT wasn't parsed.
}