Trouble finding installer file
I am planning to replace the hard drive in my Macbook pro 2012 (running 10.13.6) and am trying to create a bootable macOS High Sierra USB in case I need it. I cannot find the installer file anywhere on the app store. It is not in my purchase history and I've tried following the link from the apple support webpage on creating the installer and it opens the appstore, but does not take me to the High Sierra installer file. Anyone know where it can be found? Thanks!
MacBook Pro 15", macOS 10.13