When we installed our Mitsubishi mini split in the garage, I was paranoid about getting the flare connections wrong and causing a refrigerant leak. The installation manual was packed with diagrams showing the exact torque specs for the line nuts and the flaring procedure to avoid kinks. You can download the official guide for your specific unit by finding your model on this page
https://mitsubishi.manymanuals.com/split-system-air-conditioners for the mitsubishi mini split manual and it even has the troubleshooting codes for the remote which saved me a service call.