In 2019, USCIS started to phase out the online appointment scheduling system via Infopass. As of September 2019, you can no longer make an appointment online to visit a USCIS office.
Instead, you must call USCIS Customer Service first. If USCIS cannot answer your question or resolve your issue over the phone, they may, under their discretion, schedule an appointment for you.
Immigration applicants can also submit online requests for in-person meetings. USCIS will review your request and decide whether to arrange an appointment.
So in short, you can no longer schedule an appointment by yourself, and talk to a USCIS official face-to-face. This used to be very efficient and helpful, when people simply got stuck in the process, or had an emergency that can really benefit from visiting a USCIS office in person.
From USCIS' standpoint, they probably believe that most of the issues can be taken care of over the phone, and people don't need to visit an office, which occupies more resources than necessary.
If you feel like you must visit a USCIS office, you may still be able to do it. It's just a lot more complicated:
If you are outside the United States, you can actually schedule an appointment with an USCIS international office. Please go to this page and make an appointment. Keep in mind that USCIS is planning to close most overseas offices and will keep open only seven: Beijing and Guangzhou, China; San Salvador, El Salvador; Guatemala City, Guatemala; New Delhi, India; Nairobi, Kenya; and Mexico City, Mexico.