You came to the right place. You can sign up for a First Dollar HSA here. Alternatively, employees are often offered the opportunity to open an HSA account through the HSA provider that is selected by their employer.
Since your account is tied to you and not your employer, you can move your HSA to any provider who offers an HSA (such as First Dollar). Individuals who may get their health insurance through an exchange or marketplace can open an account directly with any HSA providers who allow it (ahem, like First Dollar).
Source: "Publication 969 (2018), Health Savings Accounts and Other Tax-Favored Health Plans.”