Sorry, seems like I missed your questions.
For your second paragraph, I believe the question of morality is indivisible from meaning.
So: if there's no objective meaning to the Universe then there's no basis for objective morality within this Universe.
Your question is 'How does the existence of God create objective morals?'... well, my answer would have to be somewhere along the lines that the Universe was created with intentionality, from one conscious point-of-view, and for a purpose (i.e. a God point of view)... to drag that down to a mundane level, when we come across a board game, we typically don't suppose it came about by chance, ..instead.. even if as a toddler.. we don't ever think it found its way onto the coffee table by enormous luck, we recognise it as a designed experience, with its own rules and - to some extent - it exists to develop certain qualities in the participants.
The Universe is the same sort of thing, but on a much bigger scale, of course.
If you went to a Chess convention would you incredulously ask all the attendees whether there was intelligence behind the creation of the rules of Chess, ..or it had all just happened as some sort of accident of nature?
And yet nature, as it is, is trillions of times more complex than Chess, yet you don't really question how that could come about... because, like almost everyone else here, you've spent decades being indoctrinated into philosophical naturalism (Coincidence Theory)... so.. all physical laws are just some kind of coincidence, despite them all being astronomically necessary to create even a rock, never mind you.... etc...