The basic request isn't complicated, so you can grab some library in your favorite language and just do it.
Obviously, making requests cost Anlas based on your subscription (so, the below will generate within the free Anlas for Opus subscriptions, but if you make the image large or increase steps a lot then it won't!)
It is basically just:
A POST request to https://api.novelai.net/ai/generate-image
The body
of the request should be JSON, in the form of:
{
// The input to the prompt.
// Note that this doesn't automatically include the 'masterpiece, best quality' that the website prepends! You have to add that yourself.
"input": "toaster, rgb, gaming, neon, realistic",