The attorney appointed to represent Jo-simar Badillo-Ortiz has moved for leave to withdraw and has filed a brief in accordance with Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), and United States v. Flores, 632 F.3d 229 (5th Cir. 2011). Badillo-Ortiz has filed a response. The record is not sufficiently developed to allow us to make a fair evaluation of Badillo-Ortiz’s claims of ineffective assistance of counsel; we therefore decline to consider the claims without prejudice to collateral review. See United States v. Isgar, 739 F.3d 829, 841 (5th Cir. 2014).

We have reviewed counsel’s brief and the. relevant portions of the record reflected therein, as well as Badillo-Ortiz’s response. In his response, Badillo-Ortiz disputes the drug quantity for which he was held accountable. Badillo-Ortiz’s trial counsel did not object to the drug quantity at sentencing. Because drug quantity is a factual finding, and Badillo-Ortiz failed to properly object in the district court, Badil-lo-Ortiz’s drug quantity challenge cannot succeed on plain error review. See United States v. Conn, 657 F.3d 280, 284-86 (5th Cir. 2011). We therefore agree with counsel’s assessment that the appeal presents no nonfrivolous issue for appellate review. Accordingly, the motion for leave to withdraw is GRANTED, counsel is excused from further responsibilities herein, and *395 the appeal is DISMISSED. See 5th Cir. R. 42.2.