@sorieibrahim, When you have an electronic device with an internal battery, that works when plugged into power / charger, but shuts off the second you unplug it, you have to replace the internal battery.
Lithium batteries (as all batteries) have a limited lifespan, and they degrade over time. A 2016 model now has a battery that is coming up on 7 years, which is old in battery time.
You’ll need to source a replacement battery, use a reputable vendor as a lot of those eBay and a lot of the Amazon batteries are pure scams. Then you have to open the device, unplug and remove the old battery and replace with the new replacement battery.