hi, i got a anker power core III elite, how can i use it to charge my microsoft surface tablet. Please help

Take a fitting cable and try it.
Could work or not, depends on the output and the input, which I don’t know.
Otherwise ask the support.

You need to use the special charging cable that came with the Microsoft surface and plug it into the USB-C port on the powerbank you brought. Make sure no lights are on the powerbank when plugging the cable in