You can easily Google this and find that there is no genetic test for autism. There are other genetic diseases that tend to also cause autism, but most autistic people don't have any known genetic reason.

Since you are worried that you may have autism, please don't donate sperm just to get a free genetic screening. Autism is diagnosed from a neuropsychiatric exam.

If you are interested in a free genetic screening, volunteer for the NIH's All Of Us research project. https://allofus.nih.gov/