Hosting add on domain set up prior to moving domain

I added an addon domain and installed wordpress on it and im trying to figure out how to get to the wordpress site so i can configure it before we move the current site to it. We are moving the current site form another host to this host but would like to get it all configured. It alwyas redirects me to the domain name we are looking to move so we can access wordpress to configure.  Is there a temp url? Ive tried every solution i can find (using ip address and username) etc.  Thank you!