To enter Reforge, you need to complete an application form. Keep in mind that the community is looking for certain profiles to join. If you work in product management, marketing, engineering, and other technology fields, you can join. Overall, if you are an operator working on growing digital products, you will get accepted in Reforge (you do not have to be an expert!).
Additionally, the community prioritizes applicants in tech companies that are post-product market fit. They do not currently serve early-stage startups and non-digital business models.