Transgender women (TW) have unique challenges related to HIV prevention medication adherence. Left unaddressed, these challenges will prevent TW from accessing the promising long-acting HIV prevention tools in the development pipeline. This study will develop a replicable process to tailor the delivery of these tools and an adherence intervention (that will include an mHealth app) to the needs of TW, using the example of inert injectable cabotegravir. Work builds on a pilot study to identify tailored methods to deliver injectable cabotegravir in TW, such as self-injection and injection by a healthcare provider at at "drop-in" clinic. The investigators will use qualitative methods (e.g., interviews, group discussions called "Design Sessions") to design the adherence intervention and the mHealth app. Then, investigators will execute a partially randomized patient-preference trial to determine if TW are able to use tailored injection strategies (self-injection or injection by a healthcare provider at "drop-in clinics") to improve adherence, compared to a control group of TW who will engage a protocol based on HPTN-083/084. This will serve as a "proof of concept" for the future R01 that will test this on a larger scale. Research and training will take place at NYSPI/Columbia, in affiliation with, 1) Project AFFIRM, a study of transgender identity (R01HD079603; PI: Bockting), that will provide infrastructure for critical research activities (e.g., recruitment), and 2) SLAP-HIV, a clinical trial to produce a long-acting form of cabotegravir (e.g., injection; UM1 AI120184; PI: Hope). SLAP-HIV will provide clinical oversight (e.g., ensure tailored delivery strategies are feasible).