If they respond that they are open to meeting, make sure you prepare for this meeting. Read up some more papers they have published and prepare a list of questions to keep the conversation going. You should also be prepared to answer questions. The worst thing you can do is to show up unprepared and unprofessional (e.g., not dressed presentably, showing up late to the meeting), and with the attitude that this meeting is merely a formality. This meeting is likely the most important step in joining a research lab. Professors want to know that you’re dependable, interested, curious, and will be a productive member of the lab.