Is a defendant required to obtain a certificate of probable cause to appeal his no contest plea?

^2. Defendant's no contest plea restricts the scope of the appeal before us. Since the lower court did not issue him a certificate of probable cause, defendant's appeal is limited to "postplea claims, including sentencing issues, that do not challenge the validity of the plea." (People v. Cuevas (2008) 44 Cal.4th 374, 379.) He is not required to obtain a certificate if he is appealing "issues regarding proceedings held subsequent to the plea for the purpose of determining . . . the penalty to be imposed." (People v. Buttram (2003) 30 Cal.4th 773, 780.) Defendant's appellate arguments are limited to his sentence and, therefore, are about matters subsequent to his plea. To the extent he might intend his arguments to challenge the validity of his negotiated disposition itself, as is suggested in his second notice of appeal, we disregard these issues.