wordpress puts the each author as admin in post

hi, i am building a website and the website allows different people to submit articles. the articles go live straight away. even though each author has their own username, the post is always published with the owner being admin and not the actual owner.

so, for example if someone wrote about donald trump leaving office, and the author was hilary clinton, it would not put her down as the author and would instead have admin down. is there a way i can solve this