If you don't know beta'ing is, it's when you proofread and suggest edits on someone elses work. Its a term usually saved for fanfiction. I do beta'ing over google docs. What you need to do is copy your fic into google docs, create a shareable link that allows people to comment. DO NOT LET ME EDIT. it is very dangerous to share your work to strangers online and allow them to edit. commenting allows me to suggest things that you can reject or accept. After you create the link to share, you will then add me as a friend and message me the link.