The article emphasizes the potential of hydrogen integration in Renewable Energy Communities (RECs) to enhance grid flexibility, stability, and economic benefits. Currently, most hydrogen production relies on fossil fuels, but the shift towards using renewable energy sources (RESs) with electrolyzers presents a promising solution for grid management and energy storage. Research underlines the importance of deeply integrating hydrogen production into power system planning to offer flexibility and stability in future electric power systems. Various studies propose models and strategies to optimize the integration of hydrogen, renewables, and multi-energy systems into grid operations, aiming to maximize economic benefits and support grid stability. The proposed operation strategy for RECs includes sector coupling resources such as RES generation systems, battery energy storage systems (BESSs), and electrolyzers connected to the grid, along with controllable loads for demand response services. Additionally, an ancillary service of reactive power for voltage regulation is suggested, offering economic benefits to community members. Overall, the article advocates for the comprehensive integration of hydrogen into energy systems to enhance grid management efficiency and support the transition to sustainable energy solutions.