You would have to have something in your background and resume that appeals to someone like me, a tenured professor of CS (now retired, though). I have to say that, from what you say, I would be very skeptical. You would need to find some way to convince (people like) me that you actually have the skills, not just "certificates".
The problem is that when you take a standard course of study from a university, people understand what that means. We have a basic trust of colleagues elsewhere that if they say you are ready then (a) they have personally evaluated you in some way and (b) you meet their own standards of excellence, which are probably similar to my own. With online courses it is very difficult to be able to say the same thing. What, in particular, does it mean that you have such a certificate. It could be worthless and mean nothing more than that you paid for a course, whether you gained anything from it or not. It is hard for people to evaluate how much actual expertise you gained through practice and how much feedback you got on your work. How high was the quality of whatever work you did?
That isn't to say that you don't have the required expertise, but certificates alone, from commercial businesses especially, aren't proof that you do.
So, to be successful, you will need some way to convince people of the quality of something that is different from what traditional students are able to do. If you can do that, then you will have a chance. But many of us will be very skeptical.
And one problem is that if you have a slot in a doctoral program, then someone else doesn't. It isn't an unlimited resources. Your road isn't impossible, but it is definitely uphill.
However, if you can establish a personal/professional relationship to a faculty member at a doctoral institution and convince them of your expertise, the road might (might) get easier.
