WordPress Install requests a user name but it does not have an input field

My site got hacked through my hosting. Their solution was to transfer the hosting within the company and then use backup files to create my sites again. The site works, but when I try to log in it comes up with a wordpress install screen. It has an option to put in the site name with an input field and an email again with an input field, but next to the user name it has ‘users already exist’ instead of the input field. I try to proceed, but it has the error stating that it would like valid user names. I have nowhere to put the valid user name!