You don’t have to do a standardized test.
https://hslda.org/teaching-my-kids/testing-evaluation
https://hslda.org/post/how-to-comply-with-virginias-homeschool-laws
“Each year by August 1, you must provide to your superintendent an evaluation showing that your child has achieved an adequate level of educational growth and progress. (This does not apply if your child was 5 or younger on September 30 at the start of the school year.)
Results of any nationally-normed standardized achievement test showing the child attained “a composite score in or above the fourth stanine” (i.e., 23rd percentile)—this could be an ACT, SAT, or PSAT score;
An evaluation letter from a person licensed to teach in any state, or a person with a master’s degree or higher in an academic discipline, who knows about the child’s academic progress, stating that the child is achieving an adequate level of educational growth and progress;
Another type of “evaluation or assessment which the division superintendent determines to indicate that the child is achieving an adequate level of educational growth and progress.” (If you plan to submit this type of assessment, you should discuss this with the school system early in the school year.)”
If your child wasn’t 6 by September 30, you don’t have to do anything. If they were 6, you can have an evaluator or some other measure (likely a portfolio) agreed upon with superintendent.