That's not what intelligent design usually means in this context.
It refers instead to a supernatural agency which though unspecified is by inference the Christian God and which by cleverly tinkering with reality brings into existence things ─ typically biochemical things ─ that can't come into existence through the ordinary operations of nature.
As I said, the number of authentic examples of intelligent design in this sense remains zero.
Likewise the number of authentic examples of magic ─ the alteration of reality independently of the rules of physics (the rules of reality), usually just by wishing, and necessarily implicit in the 'intelligent design' process ─ remains zero. Indeed, I'm not aware of any explanation, any testable hypothesis, as to how magic might work at all as an aspect of reality. So as at 2019 July it's entirely without credibility as an alternative to natural processes.
On all the available evidence, then, we conclude that life can come into existence by the ordinary operations of nature, because life in fact exists as part of nature ─ and on this planet had done so for around 3.5 bn years before there were humans ie before even the concept of gods existed.
I don't know if you keep an eye on the progress of investigations into
abiogenesis, but the number of relevant discoveries keeps accumulating; so I think it's not a wild guess that we'll get a working description of the natural processes involved in the next decade or two.
By the way, further to what
@Audie said, 'proof' has two distinct meanings, which we could think of as the mathematical and the legal. In maths and other formal systems eg logic, it's possible to say that within this system if A then [it MUST be] B. The highschool theorems of geometry are proofs of this kind. In much the same way, on the old mechanical adding machines, if you depress the 5 key, the plus key and the 4 key and turned the handle, you MUST get the answer 9. (These days the same thing is electronic, of course, but the machine is somehow more graphic.)
However, out in the real world, where law and science operate, 'proof' means something less than the mathematical [MUST BE] or [CAN ONLY BE] ─ we have to be satisfied that on the balance of possibilities the answer is B, or beyond a reasonable doubt the answer is B, or on all of the evidence we have the answer is B. You may have noticed that science accepted the reality of the Higgs boson when the evidence from the CERN experiments took the possibility of error below 1 in a million, which is the agreed threshold for that context.
That's why in science I always prefer the word 'demonstrate' to the word 'prove', though both are available.
I'm likely telling you what you already know; but the contrast with the subjective standards of 'truth' in much of religion is stark.