This study aims to explore the practice for leading the expansion of the access to and application of digital technologies in K-12 education at the municipality level. Participant observations were used to collect the data in a network with three Swedish municipalities. The study drew on the theory of practice architecture as an analytical tool to understand the practice. The findings indicate that leadership in digitalizing K-12 education should involve collaboration and a comprehensive viewpoint that facilitates the expansion of access to and application of digital technologies and a mutual understanding of the challenges and opportunities digital technologies present in K-12 education. Understanding the significance of digital technologies in K-12 education holds great importance for how digital technologies are prioritized in schools. Further, the findings show how school organizers' support of teachers and school leaders affects how digital technologies are expanded in K-12 education and how digital technologies are applied in teaching, affecting equality within schools and the quality of teaching. Therefore, school organizers' digital competence is important.