American F4 immigrant visa refused, help!

Fill in the materials according to the requirements of immigration. It seems that what you said is not only that you lack materials, but also that the other party lacks them. Comparatively speaking, F4 visa has the lowest probability of refusal and is the safest immigrant visa, so it is better to relax and provide it to the embassy according to the facts, and then wait patiently for 8- 12 years.