Efficacy and Safety Study of Treprostinil Palmitil Inhalation Powder (TPIP) in Participants With Pulmonary Hypertension Associated With Interstitial Lung Disease (PH-ILD)

Inclusion Criteria * Diagnosis of PH World Health Organisation (WHO) Group 3 associated with ILD \[including but not limited to idiopathic interstitial pneumonia (IIP), chronic hypersensitivity pneumonitis (HSP), connective tissue disease-associated interstitial lung disease (CTD-ILD), combined pulmonary fibrosis and emphysema (CPFE). * Confirmation of fibrotic interstitial lung disease by centrally overread computed tomography (CT) scan performed at Screening or within prior 12 months. * PH confirmed by right heart catheterization (RHC) at Screening or within 12 months prior to Screening, with the following hemodynamic findings: * Mean pulmonary arterial pressure (mPAP) \>20 millimetre of mercury (mmHg) and * Pulmonary capillary wedge pressure (PCWP) of ≤15 mmHg and * Pulmonary vascular resistance (PVR) ≥4 wood units (WU). * 6 Minute walking distance (6MWD) ≥100 and ≤500 meters at two 6 minute walking test (6MWT)s at Screening performed at least 4 hours apart, with the difference between the 2 distances ≤15%. * Participants receiving chronic medication for underlying disease (e.g., antifibrotic, immunomodulators, immunosuppressants, etc.) and/or phosphodiesterase 5 (PDE5) inhibitors, should be on this treatment for ≥90 days and on a stable dose for ≥30 days prior to Screening. * Capable of giving signed informed consent as described in Section 10.1.5 which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. Exclusion criteria * Diagnosis of Pulmonary Hypertension WHO Groups 1, 2, 4, or 5 (including sarcoidosis), or subtypes of PH WHO Group 3 other than interstitial lung disease. * Primary diagnosis of chronic obstructive pulmonary disease (COPD) and/or forced expiratory volume in 1 second (FEV1)/ forced vital capacity (FVC) \<0.7 (based on screening or historical spirometry within the prior 6 months). * Clinically significant left heart disease: * evidence of clinically significant left-sided valvular heart disease, * left ventricular failure with left ventricular ejection fraction (LVEF) \<45% * echocardiography findings at Screening suggestive for postcapillary (or combined pre and postcapillary) PH, heart failure with preserved ejection fraction (HFpEF), or heart failure with mildly reduced ejection fraction (HFmrEF), including left atrial volume index (LAVI) \>34 millilitres per metre square (mL/m\^2) * unstable ischemic heart disease * unstable arrhythmia, including uncontrolled atrial fibrillation (rate-controlled arrhythmia or paroxysmal atrial fibrillation is allowed) * Evidence of chronic thromboembolic disease or recent (within 6 months of Screening) acute pulmonary embolism. * Known hypersensitivity or contraindication to treprostinil or TPIP or TPIP formulation excipients (e.g., mannitol, leucine). * Current use of cigarettes or e-cigarettes: An adult who has smoked at least 100 cigarettes in his or her lifetime and who currently smokes either every day or some days. * Current use of inhaled marijuana, recreational or medical (current use defined as used at least one or more times during the past 30 days prior to Screening) or expected use during the study. * Any other medical or psychological condition including relevant laboratory abnormalities at Screening that, in the opinion of the Investigator, suggest a new and/or insufficiently understood disease and/or may present an unreasonable risk to the study participant as a result of his/her participation in this clinical trial, may impede their ability complete the study or the study assessments or confound the outcomes of the trial. Note: Other protocol defined inclusion/exclusion criteria may apply.