Use ESC plus UBEC
ESC stands for Electronic Speed Controller. It converts the PWM signal from the flight controller or radio receiver, and drives the brushless motor by providing the appropriate level of electrical power.
BEC stands for Battery Elimination Circuit. It’s just a fancy name for voltage regulator, which converts main LiPo battery pack voltage to a lower voltage (e.g. 2S 7.4V, 3S 11.1V or 4S 14.8V to 5V). BEC is usually built into ESC, and as the name suggests, it eliminates the need for a separate battery to power the 5V electronic devices.
UBEC stands for universal BEC or sometimes ultimate BEC. It’s used when ESC doesn’t have built-in BEC, or standalone power system is required. They generally are more efficient, more reliable and able to provide more current than BEC. The UBEC is connected directly to the main battery of the multicopter, the same way as an ESC.
oscarliang.com/what-is-esc-ubec-bec
No BEC
https://multirotor-parts.co.uk/product/hobbywing-platinum-pro-30a-electronic-speed-controller/
https://www.youtube.com/watch?v=OZNxbxL7cdc