This document specifies the methods and the requirements for the supersonic molecular beam injection (SMBI) fuelling technique used in experimental magnetic confinement fusion facilities. It outlines the SMBI system components, specific requirements, and inspection procedures to ensure the effective and controlled injection of plasma fuel into fusion devices such as international thermonuclear experimental reactor and demonstration power plant. This document applies to the formation of supersonic molecular beam (SMB) and usage of the SMBI technique on the fusion devices, including the specification of gas pressure adjustment, beam characteristics and injection rate requirements, as well as the procedures for verifying these parameters.