Notice: Notify installed from Huawei App Gallery is a different version compared to Google Playstore version (different license, updates, ...).
If your phone doesn't have Huawei App Gallery already installed, download it from official Huawei website.
Download Huawei App Gallery
Login or create a new Huawei account. This is required to manage app licenses, data backup, ...
Download the Notify app from Huawei App Gallery:
Notify for Mi Band
Notify for Amazfit
If you were using Notify Google version, export a backup from the old app
You will be asked to install the Huawei Services app, this is required to allow manage licenses, data backup, ...
if you don't get any message, please install the app manually Download Huawei Services app
If you have a backup, import it from the first welcome screen on Notify app (choose Import backup), otherwise continue with the pairing procedure.
Check you migrated all your required settings, once done, you can uninstall old Notify app version