It is impossible to underestimate the importance of hydrogen, especially renewable hydrogen, in the energy transition. Despite the huge potential and rising demand for renewable hydrogen, there are significant challenges that need to be overcome. One specific problem is the use of metallic equipment for high-pressure hydrogen gas applications (pressure vessels, transport networks...). These components are susceptible to hydrogen embrittlement, a phenomenon that can lead to structural degradation and severe damage. The effects of hydrogen embrittlement present a significant risk since they may shorten the life of these structures and affect their reliability and security. Therefore, the development of a numerical model to validate the design of hydrogen related systems is critical for addressing the massive industrial challenge and scientific obstacle. In this context, this study consists in developing a finite element (FE) model based on the phase field theory for hydrogen assisted fatigue. The phase field theory has recently gained a big popularity in the scientific community due to its ability to model initiation and propagation of cracks and to facilitate the integration of complex physics. In this work, the phase field theory was extended to model hydrogen embrittlement and fatigue. The FE tool thus developed integrates both mechanical modeling of the stress and strain fields, phase field modeling of damage and cracking, and modeling of the local hydrogen concentration and its evolution. Knowing that the mechanical response of the structure is sensitive to the hydrogen pressure and the loading frequency applied, different cases of applications were investigated by varying these two parameters at room temperature. Moreover, the model was employed to capture crack interaction with other defects. In this presentation, these different aspects of the FE model will be detailed as well as the different case studies that will demonstrate the capabilities of the FE simulation tool.