okay thank you for your kindless

In BGB, the .sav automatically loads based on filename of the ROM.

For example, if your LSDJ rom is named 'lsdj494.gb', you rename your .sav file to 'lsdj494.sav'. As long as they have the same name and are in the same folder, BGB will load the .sav automatically.

If you are using multiple .sav files this can become cumbersome; I overcome this by creating multiple copies of the .gb file.
For example, I refer to my two cartridges as 'Orange' and 'Black' due to the color of the LSDJ sticker on them.
So I have two copies of the same LSDJ ROM, lsdjblack.gb and lsdjorange.gb. I keep my .savs in a different folder, then drag them my BGB folder then rename them to match the .gb file.

There's probably other ways of doing it but this is my method. I believe VBA has an option to import a battery save, but for chiptune purposes you're going to want BGB.

I'm using BGB and VBA

You're gonna have to tell us what emulator you're using, as that will effect the steps you need to take.

I tried to load the sav file created with USB SMART CARD on my PC but it failed. How can I load it?