I am not bluestacks support.
I do not think this emulator is good.
Instead of a launcher, they integrated Chrome on the first tab to display ads.
And the behavior of the emulator with tabs is very buggy.
The developers tried to remove adb and transfer it to the wrong port.
In general, this is a problematic emulator and it is not clear why you want to use it.
And if you have a problem uploading a file to it, this does not mean that you will solve it and it will become easier further.
Use the file manager from BStweaker.
Create a folder in GG, and then, through the Bstweaker file manager, place the script file there.