If you don't own a domain or host a website, set up a github account and use github pages to have a `.well-known/nostr.json` file with the content:
```json
{
"names": {
"astroc": "YOURNOSTRPUBKEY"
}
}
```
Then go to astral.ninja/anigma.io and fill the NIP-05 field with `astroc@<YOURGITHUBUSERNAME>.github.io`