From the physico-theological booklet:

“The assumption that there were countless previous attempts of universes with other laws of physics is a very problematic assumption. According to this proposal, there are supposed to exist alongside us countless universes different from ours (since the number of possible systems of laws is infinite), and in each of them different laws of physics prevail. None of us has seen them, and apparently we also cannot see them. This is an ad hoc invention only in order to escape the physico-theological straits. This is really a case of Russell’s celestial teapot (see above at the end of chapter 4), but this time it orbits the atheist’s star. He invents teapots that nobody has seen, just in order to evade the need to look for a cause of the universe.”

I’ll try to explain why I really didn’t understand the move at all.
We see a very rare universe. From life experience, if something rare happened then either something happened many times until it succeeded (there’s a whole genre of videos of extremely low-probability events that are just coincidence and not staged), or someone directed the event. Therefore there is equivalence between the explanations, and for a rare phenomenon that we see, with no intuition or hint, both are equally possible. (A Creator or a multiverse.)
The claim that multiverse is an attempt to dodge the issue and an invention already assumes in advance that there is a Creator, and therefore the multiverse, unlike the Creator, does not solve the riddle of rarity, and then of course it is unnecessary.
But if we solve the problem of rarity by means of a multiverse explanation, then suddenly a Creator becomes an unnecessary invention (because it is already given that the multiverse caused the rarity), without evidence (because He did not create the world), and He becomes only a means of escaping the multiverse claim.

In short, there is symmetry between the proposals, and choosing דווקא the Creator is begging the question. You know the multiverse is unnecessary because God already solved the problem, and God solved the problem because the multiverse is not true.

You brought only one paragraph. Read the surrounding discussion there. Everything is explained.

Up to the heading of the next chapter, it looks like a conceptual continuation of that same paragraph, just with more examples. The booklet insults the universes for being transparent, or says the atheist just makes things up for no reason (exactly like the Creator—He too is the product of an inference from complexity, and He too is inaccessible to us). But in any case, my position is not “there definitely are many universes” but “there is no more probable option between a creator and a multiverse.” The booklet does not show why a creator is more probable than many attempts.
The general spirit of the booklet assumes that something complex must also have a planner, but say all miracle stories (after filtering out the false ones among them) are just another example of special things that happened after many attempts, unlike, for example, a factory.
Each case of a complex thing has to be judged on its own merits, and because we do not know much about the creation of universes, one opinion is no more successful than the other.

And because the multiverse is a vague argument and not fully explained, exactly like a creator with an unseen will,
the reason people regard the creator as the more probable thing is precisely because of the teapot. In the parable, the teapot is popular because people were educated on it, and challenging it, in their view, requires actual proof for universes.
Here it is identical: God is the starting point and the multiverse requires proof. But if they had created some religion around the multiverse, of course they would mock the transparent god in their booklets—the one unnecessary for any explanation, invented, only made up in order to challenge their religion, and so on. From the symmetry it follows that any stance is unreasoned and the opposite stance could just as well be taken.

I’m sorry, but I have a hard time with reading comprehension at this level. All the best.

Here is an attempt at clarification and summarizing; sorry about the previous wording.

The position is not “there definitely is a multiverse” but “it is not possible to decide between an intelligent creator and a multiverse.”

The reason people regard the intelligent creator as the more probable thing is precisely because of the teapot. In Russell’s parable, the teapot is popular because people were educated on it, and to challenge it you need proof.
Here it is the same: God is the starting point and the multiverse requires proof. But if people were to invent some religion around the multiverse, then of course they would mock the transparent god in their booklets—the one unnecessary for any explanation, invented, only made up to challenge their religion, and so on. From the symmetry it follows that every stance taken (an intelligent creator or a multiverse) is unreasoned, and the other stance could just as well be taken.