Question about TOP Solar

The powerbank should charge automatically when it is outside. Does not work indoors, through the windows.

But once in principle to such solar powerbanks:
They are pretty much all crap and the information on charging times are ideal conditions... Summer afternoon sun without a cloud...
The integrated solar cells of such powerbanks are simply too small and have too little power to charge within a useful time.

Then there is some noname brand with probably quite cheap Chinese solar cells.

If you want to charge a powerbank sensibly by the sun, I would recommend one with additional fold-out solar cells, or some mobile solar cells that you can connect to a normal powerbank.