Why won't it assemble

DUDDEEE IVE BEEN TRYING TO PUT THIS ON HOURS MAN I JUST WANNA USE THE RUBBER SIDE ON HADES IS SOMETHING WRONG BRUH PLEASE HELP

DUDDEEE IVE BEEN TRYING TO PUT THIS ON HOURS MAN I JUST WANNA USE THE RUBBER SIDE ON HADES IS SOMETHING WRONG BRUH PLEASE HELP