[TQN]

Use this IDAPython script

def applySigFile():
    file = ida_kernwin.ask_file(0, "*.sig", "Select sig file to apply")
    if not file:
        print("applySigFile: user cancelled")
        return

    print("Apply sig file %s" % file)
    ida_funcs.plan_to_apply_idasgn(file)


def applySigDir():
    sig_dir = os.path.join(os.path.dirname(sys.executable), 'sig')
    sig_dir = str(QtWidgets.QFileDialog.getExistingDirectory(None, "Select Your Signatures Directory", sig_dir))
    if sig_dir == "":
        print("applySigDir: user cancelled")
        return

    for name in os.listdir(sig_dir):
        if name[-4:] == '.sig':
            name = os.path.join(sig_dir, name)
            print("Apply sig file %s" % name)
            ida_funcs.plan_to_apply_idasgn(name)

Same as til files