A few days ago I faced the problem regarding PrestaShop change APE length. So I think it will be better to share the solution with you all. There are no ways to change the APE length from PHP file you have to change the length. You need to modify the default PrestaShop table ps_customer. Running the following query will change the length of the APE field.
Run following SQL query and change the length accordingly. I am setting the length to 16.
That’s it from this article. I strongly believe there is always room for improvement. So I am open to any suggestion and feedback. Please feel free to leave what you are thinking in the comments section below. Cheers.