I'm taking photo with ESP32-CAM and saving sd card. I want to send taken photo via RF (LoRa, XBee ets.) to another arduino. I don't know where I can start about sending. I don't know how to send. Do u have any advice ?
Sure. Research Lora and XBee.
I worked with XBee for 3 years but I generally send basic data packet. So I don't know how to send an image file.
Break the image file into packets and send them the way you usually do.
Some ideas in this thread: Images or files from Arduino to PC file directory via serial
Details and links to working code are linked to below, first an early setup that required an I2C IO expander to do some of the pin switching, and without the SD card working;
And then eventually after a bit of work a wiring solution that a removed the need for the IO expander and had the SD card working as well;
The 2.4Ghz SX1280 LoRa module is by far the best choice here, it can transfer a typical 800x600 image in about 700ms, including extensive error checking.