Yes, you can buy the app with your Apple ID account and, using that same account, redownload it onto the new device when you get it. Here's how:

Option 1: If you own another iOS device running iOS 12.4 or later, you can purchase the app on that device and then redownload the app when you get the device.

Option 2: If you have a computer running iTunes 12.7 or later you can take the following approach: On the App Store on your older device gift yourself the app. In the gift email, you will find a redeem code. You can redeem this code in iTunes on a Mac or Windows computer using the same Apple ID you are using on your older devices. Next, you can redownload the last compatible version of the app on the App Store on the older device.

Option 3: If you have a computer running an older version of iTunes (older than version 12.7) you can purchase the app on a computer and then redownload the app on the iPad using the same Apple ID.