Replacement for ricotta

The brand Kite Hill makes an amazing dairy free ricotta, soy free, but it’s not easy to find and a small container is fairly expensive.
Cashew ricotta is super easy to make, and excellent for lasagna. I haven’t used it in ravioli but I’m sure it would be fine.
Be sure to buy raw cashews (pieces are fine) and just soak in cold water in the fridge overnight or a few hours. Be generous with the salt.
This recipe is the basic version, maybe five min start to finish
https://simple-veganista.com/cashew-ricotta-cheese/

There’s also basically the same process just with almonds, but of course there’s a specific almond flavor to it, and it’s not as smooth and creamy as the cashew version
https://www.yummymummykitchen.com/2017/09/vegan-ricotta.html

I also don't particularly care for ricotta in lasagna, and use a bechamel. I would suggest doing that, but consider using rice milk if you would like to avoid regular milk. You could still add in the heavy cream to add a certain roundness to it, as well as pecorino and parmesan. There are also various soy and dairy free cheese substitutes, and recipes available on the internet to make your own. My daughter worked with a lady with similar allergy restrictions, and I know she made and bought some which were considered acceptable. I had a bit of a lasagna she made using an almond milk based ricotta substitute, and it wasn't bad. Not quite ricotta, but acceptable. I think it would work in ravioli as well. I wish I had the recipe to offer you, but I think a web search would probably turn up a few you could try out. I also know that my local natural food store carries a fairly wide selection of vegan "dairy" products, including cream cheese and I think a ricotta. So maybe that's one place to consider looking.

I don't really like ricotta in my lasagna....it has a graininess that I prefer to avoid. I use a béchamel pumped up with some sharp, aged cheeses (parmigiano, grana, pecorino) instead of ricotta. I'm not sure where you stand on regular whole milk, but you could use some water and heavy cream to replicate whole milk? I then add a healthy amount of salt, a few good handfuls of cheese and a ton of black pepper.

As for ravioli, I much prefer vegetable purees over ricotta anyway. Its not really a straight sub, but veggies are so much more dynamic. I love things like winter squashes, grilled eggplant, roasted beets, peas, roasted cauliflower, sunchoke, parsnips, carrots, etc. You can add some cheeses of course, but you can really get some interesting ravioli fillings when you think beyond ricotta and ground meat.

Good luck!