I submitted my abstract (400 words) to a conference, and unexpectedly it was accepted to the poster session, not the oral one that I wish. The submission of the full paper is not mandatory for that conference. Honestly, going to that conference costs me a lot in terms of time and money, so if I have to present a poster, I would like to withdraw it. My supervisor suggested me to instead submit the full paper to a journal because I already have the full paper. I just want to make sure if it would be okay. Any advice will be appreciated!