You might want to contact your local medical equipment supply stores

A reasonable option is to contact your local medical equipment stores. Since there is a real opportunity to make sure the quality and compliance of the product to your needs.

Hi, everyone can someone recommend an online resource, where can I order such socks?

I can recommend it https://www.funnypetsocks.com/ .
Although you know, at a time when we are all forced to isolate ourselves. These are temporary requirements. As life has shown, we can adapt to any conditions. Right now, all the resources I'm talking about, internet sites, are designed so that you can have whatever you want. Of course, I would like to mention the guarantees that are provided to the buyer. So that's what I'm getting at, now you can buy better quality compression socks. But since we all strive to be individual, there is even a service that allows you to make a unique design of your socks. If you have a favorite pet, then you can order a pet face on socks. Isn't that cute?)

I'm sure you already found a solution by now, but every 2-3 years my doc gives me a prescription and I take it to the medical supply store. They measure my legs and order what I need. My DVT leg is larger than the other, so I feel more comfortable ordering this way than online. You don't have to have a prescription to order from the store I use, but it helps on the cost.