Realme
Set a Custom Ringtone from Your Own Audio Files auf Realme
Realme UI ships with a limited set of preinstalled ringtones, which makes it hard to tell your phone apart from every other Realme device around you. Fortunately, the sound settings let you pick any audio file stored on the phone and use it as your ringtone instead.
On Dual SIM devices, this setting works per card. That means you can assign one tone to your work SIM and a different one to your private SIM, so you know which line is ringing before you even look at the screen.
Where to find this setting
Open Settings ➔ Sound & vibration ➔ Ringtone. If you have two SIM cards active, choose the SIM card you want to configure first. Then tap Select from files and pick the audio file you want to use. Confirm your choice to set it as the custom ringtone for that SIM.
This method works for any audio file stored locally on your phone, including MP3 files you have transferred or downloaded. Files stored only in cloud apps need to be downloaded to local storage first, since the picker only shows files saved on the device.
If you only want to change the notification sound and not the ringtone, look for a separate notification sound option in the same menu, since ringtone and notification sound are set independently.