If you have really written it, you should be able to join. As far as I know, for example, this year's "Xinjiang Huachun Cup" co-organized by the Xinjiang Department of Education, Xinjiang Association for Science and Technology, Xinjiang Federation of Literary and Art Circles and Xinjiang Hard Pen Calligraphers Association*** "For Xinjiang's first hard-tipped calligraphy works exhibition, authors who have entered the exhibition and won awards are qualified. It should be understood that for large-scale exhibitions such as the annual exhibition, you can join the association once. For other individual exhibitions and commercial exhibitions, you need to join the association twice. For details, you can log on to the website of Xinjiang Hard-tipped Calligraphers Association