Minecraft capes?

Can you add a cape from the Mod advanced capes in Badlion client, because the mod is already in bac

If yes how

No.

The mod is also NOT in bac (and also not in LabyMod or Optifine).

Bac has its own mod and database for it (just like Labymod and Optifine).

That means I have to get an optifine cape and then insert the design?

At Optifine you can unfortunately not take completely your own pictures. Only what would be possible with a banner.

But I think that's possible with Labymod or bac