Guide for iOS devices:
- Open the Settings app.
- Tap your name, then tap Subscriptions.
- Select the Nebula app to change your plan.
- Tap See All Plans, then follow the onscreen instructions to complete the process.
For more details, you can refer to the official guide from Apple: Apple Subscription Guide.
Guide for Android devices:
- Open the Google Play app.
- Ensure you’re signed in to the correct Google Account.
- Tap the Payments & subscriptions button, then tap Subscriptions.
- Find and open the Nebula app in the list.
- Tap Manage subscription.
- Select the new plan you want to switch to.
- Choose a supported payment method.
- Tap Buy or Subscribe to confirm.
For more information, you can check the official guide from Google: Google Play Subscription Guide.