Backing up replacement iPad

[Alwyn]

In 2017 I lost my iPad. I bought an iPad Air recently but, when I connect it to my iMac the only choice is to set it up as a new iPad or restore it from the old one. If setting it up as a new one involves losing all its current settings I don’t want to do that. If the only way to back it up with the current settings is by deleting the backup from the old iPad I would be prepared to do that. Is there a third alternative allowing the previous backup to be retained and allowing the current settings to be kept?

[ferrarr]

No, that's not what "Setting up as new" means, in this situation. Setting up as new, means allowing it to work with this computer and iTunes.

Now, if the replacement iPad Air, was already synced to a different computer, then that will be the case, where everything will be erased. Did you buy the iPad Air New, or used?