The primary purpose is to evaluate the safety and efficacy of NAL ER for the treatment of chronic cough in participants with Idiopathic Pulmonary Fibrosis (IPF).

Inclusion Criteria:

• Diagnosis of IPF as determined by the Investigator based on American Thoracic Society (ATS)/European Respiratory Society (ERS)/Japanese Respiratory Society (JRS)/Latin American Thoracic Society (ALAT) clinical practice guidelines.
• Chronic cough for ≥8 weeks prior to Screening.
• PGI-Severity Score ≥ 2 at Screening.
• Forced vital capacity (FVC) ≥40 percent (%) of predicted at Screening.
• Diffusing capacity for carbon monoxide (DLCO) ≥25% of predicted during Screening or within 12 weeks prior to Screening.
• Participants who are currently taking antifibrotic medication (e.g., nintedanib, pirfenidone, nerandomilast) should be on a stable dose for at least 6 weeks prior to the Baseline Visit.

Exclusion Criteria:

• Clinical diagnosis or clinical suspicion of an upper or lower respiratory tract infection in the last 8 weeks prior to the Screening visit or during Screening.
• Hospitalization for any respiratory illness (including acute exacerbation of IPF) within 2 months prior to Screening.
• Diagnosed sleep apnea or currently on any treatment for sleep apnea [example (e.g.), Continuous Positive Airway Pressure (CPAP)].

Note: Other protocol-defined inclusion/exclusion criteria may apply.