My challenge is this:
If you claim that there is proof that ABA has proof or has a scientific basis, can you show any evidence that has either evidence from a double blind test*, or a test with a significant (in the high hundreds or in the thousands) sample size. The challenge is any one of the three questions below.
All would be nice, but I’ll settle for one.

I am writing this in Autism Awareness Week, 29th March – 4th April 2021, and also Autism Awareness Month, April 2021.
There are a lot of people and organisations out there offering ABA therapy, most are making a claim that they are proven, I have yet to see any of them link to the research which they say is proven. Here is your opportunity, if your claims are based on scientific fact you have nothing to fear.
I also hear misleading information. Some ABA therapists are saying that an autistic child will not develop without taking ABA therapy. If so, where did all the adult diagnoses come from? How did these people develop without having ABA?
I also hear from autistic adults who had ABA therapy as a child that all it did was make them mask who they were, and that this masking cannot be maintained and leads to the meltdowns it should prevent and because of the trauma of the therapy. Could you address these also.
These are all genuine questions, not trick questions.
*A type of clinical trial in which neither the participants nor the researcher knows which treatment or intervention participants are receiving until the clinical trial is over. This makes results of the study less likely to be biased.