The hoverboard battery is approx. 12V -14V. Do you suggest me which powerbank of anker is best to charge the hoverboard
How many amps?
There are many companies that make voltage converter USB cables that would allow you to the power bank of your choice.
Don’t know the amps
do you tell me how to find amps from volts?
It doesn’t work that way. If you look on the amazon webpage for your specific hoverboard model, it will probably say how many amps it charges At in the specifications.
It should be printed somewhere near the charging port on your board.
If you provide the model number I’d be more than happy to look it up for you.