Let's make sure 1SE is backed up on your device! We'll use iCloud, but you can do all this with a Mac or PC.
If you have a 1SE Pro account, follow these steps to back up your data.
Back up your device with iCloud
Before you begin, make sure 1SE will be included in your iCloud backup by following these steps:
Make sure your phone is fully charged and connected to Wi-Fi.
Go to Settings > [your name] > iCloud.
Tap iCloud Backup and select "This iPhone" from the ALL DEVICE BACKUPS list.
Scroll through the apps list and ensure 1SE is enabled.
Return to the previous screen and tap Back Up Now.
Stay connected to your Wi-Fi network until the process completes. It may take a while.
Yay! Congrats, you now have a backup with 1SE to restore.
If you'd like a more detailed step-by-step for iCloud or Mac/PC backup, check out Apple's help article.
VERY IMPORTANT: Please keep in mind logging into iCloud on your new iPhone isn't the same as an iCloud backup. 1SE is NOT saved in your iCloud account. Only basic data like notes, mail, and contacts are. You'll need to do a backup via iCloud or a computer.