Steps to find the solution:
Try an alternative certified cable that you know works on other devices.
Verify the cable is well inserted.
Use a certified 5V charger.
Try a different power source.
Make sure the charging port is dry, clean, and not damaged or loose.
Contact the seller for additional help.
During normal charging period, LED signals flash as follows:
Red LED flashes when the battery level is below 20%.
Blue LED flashes when the battery level is below 60%.
Green LED flashes when the battery level is above 60%.
Green LED stays on when the battery is fully charged.