I keep getting message as “accessory is not supported on this device” quiet often on my screen

It's my understanding that you're getting messages that state “accessory is not supported on this device”. I may be able to help you with this. Check out this article: If your iPhone, iPad, or iPod touch won‘t charge

If an alert says that your accessory isn't supported or certified

These alerts can appear for a few reasons: Your iOS device might have a dirty or damaged charging port, your charging accessory is defective, damaged, or non Apple-certified, or your USB charger isn't designed to charge devices. Follow these steps:

1. Remove any debris from the charging port on the bottom of your device.
2. Restart your iOS device.
3. Try a different USB cable or charger.
4. Make sure that you have the latest version of iOS.
5. Contact Apple Support to set up service.

Let me know if this helps.
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Cheers!