Example:
According to the International Organization for Standardization (2018)...
OR
... (International Organization for Standardization, 2018).
Corporate author. (Year). Title (Standard Number). URL
Example:
International Organization for Standardization. (2018). Occupational health and safety management systems—Requirements with guidance for use (ISO Standard No. 45001:2018). https://www.iso.org/standard/63787.html