Advice from cat parents …

I actually just found out a lot on this topic that I had no clue of before.

Cats are mostly solitary animals. They aren't pack animals like dogs so they only really seek out the company of other cats for mostly breeding.
It doesn't mean they are anti-social but they don't have that drive to belong like a dog.
Also when a dog bonds it's because of a chemical released in the brain called Oxytoin which happens to be the same in people.
But when a cat bonds it is more through dopamine and endorphins. So the dog feels connection like a human and the cat feels a reward like drugs in humans.

So anyway. Just let them work it out because they do acclimate pretty fast.

It will happen naturally or it won’t. I did the same thing and it took two years for them to get comfortable enough with each other to sleep together.
It didn’t work out how I hoped

To help an older cat bond with a kitten, you can follow these steps:
"Catster

Quarantine the kitten initially to allow your older cat to get used to its scent.
Mingle their scents by rubbing a cloth on one cat and then the other.
Make your home cat-friendly with separate resources and territory.
Feed them separately to avoid competition.
Give visual access to each other without forcing interaction.
Allow physical introductions under supervision.
Encourage bonding by giving treats at the same time and putting their food bowls close together."

I had 2 cats once. . Never again. But every cat is different.

Sorry, but that just may not happen. That was our thinking when one of our cats ran away. Unfortunately, I think they all they do is tolerate each other

You can't force it
You have to let them figure it out
Only break up fights if they are viscious ... most fights aren't
Once the older cat figures out the new one isn't leaving things should slowly improve

Ouch

Cats have varying personalities. So time I suppose.

They will eventually it takes time

Superglue.

Or time....

Superglue for Cats(R)

JUST KIDDING

They’ll do what they what when they want

Give it a week or so, your older cat will soon treat the kitten as its own.