Verizon FiOS would only be available if Verizon Core (Ma Bell) was the RBOC for the town. If Verizon is not the RBOC, then the power converter & backup battery unit came from some other location. In places where Verizon installed FiOS, but, subsequently exited, the new provider would continue providing the service under a different name.
Verizon Core is trying to get away from wireline communications. The company has been installing 5G OTA equipment in test markets as a way to deliver fiber based services without having to hang fiber drops or trench the ground to lay conduit along property lines.
Thanks very much for providing the pictures in your post. They are a big help in knowing our next best step for you. I'm here to assist with your options. I do agree with Ann154. If you would like to inquire further, your best bet would be to contact Verizon FiOS in their community forum: Verizon Forums – Welcome to the Verizon Fios® Community This gives you a way to post the same pictures, and get assistance from their team. I'm certain that the pictures will be a big help, especially since you have the equipment, but you don't have an account. If you prefer, you can call them directly at 800-300-4184. I really hope this information is helpful for you.