Unfortunately, there is no way to transfer the subscription plan and your account between iOS and Android platforms.
You can only transfer your subscription from one platform to another by contacting our support team and providing us with the screenshot of the payment for the subscription or a screenshot from your subscription list on App Store or Play Market.
After this, we will be able to check your subscription and will give you the activation links to restore your premium access.
Also, if you have unused credits on your old device, please provide us the screenshot of your in-app balance on the old device, or you can provide us the screenshot of the payment for these credits. You should contact us through the "Settings" in the Nebula app on your new device using the "Support (Contact us)" feature, to give all necessary info to us. Please see how to find the "Settings" menu here: How to find the settings menu
We are sorry for this inconvenience.