How to access a non-static method in dynamic class with LambdaMetafactory during the runtime

I am trying to use LambdaMetafactory to replace reflection,but I have a problem.If I use a specific class then it works well,just like this:

        MethodHandles.Lookup lookup = MethodHandles.lookup();
        MethodType type = MethodType.methodType(ResponseMsg.class,Map.class);

        MethodHandle mh = lookup.findVirtual(TestService.class,"testMethod",type);

        TestService ins = TestService.getInstance();

        MethodHandle factory = LambdaMetafactory.metafactory(
                lookup, "apply", MethodType.methodType(Function.class,TestService.class),
                type.generic(), mh, type).getTarget();

        factory.bindTo(ins);

        Function lambda = (Function) factory.invokeExact(ins);

But if I use Class<?> to replace the specific class ,then it won't work,just like this:

    public static Function generateLambda(@NotNull Class<?> cls,@NotNull String method) {
    MethodHandles.Lookup lookup = MethodHandles.lookup();
    MethodType type = MethodType.methodType(RETURN_TYPE,PARM_TYPE);

    try {
        MethodHandle mh = lookup.findVirtual(cls,method,type);
        Object instance = getInstance(cls);
        if(instance == null) {
            return null;
        }
        MethodHandle factory = LambdaMetafactory.metafactory(
                lookup, "apply", MethodType.methodType(Function.class,cls),
                type.generic(), mh, type).getTarget();

        factory.bindTo(cls.cast(instance));

        return (Function) factory.invokeExact(cls.cast(instance));
    } catch (Throwable e) {
        logger.error("get Function fail, cause :" ,e);
        return null;
    }
}

Here is the exception:

java.lang.invoke.WrongMethodTypeException: expected (TestService)Function but found (Object)Function
    at java.lang.invoke.Invokers.newWrongMethodTypeException(Invokers.java:298)
    at java.lang.invoke.Invokers.checkExactType(Invokers.java:309)
    at com.utils.cache.ClassUtils.generateLambda(ClassUtils.java:182)

The Line 182 is:

return (Function) factory.invokeExact(cls.cast(instance));

I know just use static method can solve this problem,but I want to know is there any other way to solve it without changing the non-static to static.