The `auth.login` method of the JS SDK allows passing custom, which is useful for custom authentication providers. For example:
```ts
const response = await sdk.auth.login("customer", "phone-auth", {
phone
})
```
However, the `auth.register` method doesn't allow that, so we can't do the following:
```ts
const response = await sdk.auth.register("customer", "phone-auth", {
phone
})
```
Instead, we'd have to use the `client.fetch` method.
This PR fixes the input type of the payload passed to the `register` method to be similar to that of `login`, which would allow using it with custom authentication providers
9f376ff1f1