Sometimes you just have to grab them and put them in by force. The quicker the better, usually helps if there are two people. It’s the only way we can get ours in but it’s for their own good.

Top loading carrier. So much easier to just drop them in and close the lid. Easier to get them out at the vet too.

Get some gabapentin from your vet

I don't bring the carrier downstairs, that is too much warning! Last time I took our cat upstairs to it, giving him a cuddle. He maybe though we were going for a nice nap! Had the carrier open ready, cat in, Dreamies already in there as a distraction. Not sure how often that would work though without the poor lad associating upstairs with the carrier!

I will second Gabapentin and desensitization. Picking them up and just throwing them in might make the whole ordeal traumatizing and it’ll become increasingly hard every time it’s a negative experience to the point she won’t even go close to a carrier. Turn it into a safe space, make it comfortable, give her treat and her regular food in the carrier, turn it into something not to be scared of (as opposed to just forcing her in) If desensitization doesn’t work, Gabapentin might calm her enough.

Catnip?

Leave the carrier out, but also, get a top-opening carrier so it can sit there like an open box. Also means that the top can be taken off at the vets and they can just sit in the carrier for most, if not all, of the examination.

This - sometimes there is no coaxing, just grab them and shove them in saying “imsorryimsorryimsorry” the whole time. They’ll be pissed but they’ll get over it.

Put the cat in a pillow case BEFORE putting it in the carrier.

The vet showed me a trick of putting the carrier on the edge of the table so cat has less choice of where to go?