CameraFTP is a cloud service provider. Sorry we don't make or sell IP cameras. We have tested and listed quite a few IP camera brands and models. Please visit www.cameraftp.com and click Cameras on top of the web page. You can find a lot of Setup Guide documents for different camera brands/models. Most battery-powered IP cameras are proprietary and less functional than regular IP cameras. Reolink battery-powered IP cameras are usually in stand-by mode to save power. It does not support standard protocols like RTSP, ONVIF and FTP. It supports SMTP. You can configure it to upload images to CameraFTP via the SMTP (email) protocol. Unfortunately, it does not support continuous recording; and it can only upload very few images for each event. You can watch this video for more info about how to configure it to upload image snapshots to CameraFTP via SMTP/email.
You can use a Mobile 4G/5G Access Point instead. With a single mobile access point and a single data plan, you can have multiple regular IP cameras. This can solve your Internet connectivity problem, but not your power supply issue. You might be able to use a solar panel and external rechargable battery to power the IP camera. If so, most non-proprietary IP cameras will work for you.