Can a defendant obtain review of issues requiring a certificate of probable cause under section 1237.5 and rule 8.304(b)(1)?

A defendant may not obtain review of issues requiring a certificate of probable cause unless she has complied with section 1237.5 and rule 8.304(b)(1) "fully, and, specifically, in a timely fashionthat is to say, unless [s]he has done what they require, how they require, and when they require." (People v. Mendez (1999) 19 Cal.4th 1084, 1099 [construing predecessor to rule 8.304(b)(1)].) In the absence of such compliance, the appeal is not "'operative'" and the reviewing court must dismiss it. (Id. at pp. 1095, 1096.) We may not overlook this deficiency and grant relief from default. (See id. at p. 1098.)