how do I sign in in order to get 4 voices in Dorico for iPad ?
If you’ve currently got your iPad in portrait orientation, switch it to landscape. Hopefully you can see the application menu at the right-hand end of the toolbar: it’s at the very right-hand end, following the share icon. Open the application menu and tap Sign In, then follow the prompts to sign in with your Steinberg ID.
If you can’t see the application menu even after turning your iPad into landscape orientation, I’m very sorry for the inconvenience, and we’re working on an update that will make the menu visible on iPads with all sizes of display as soon as possible.