The method can be found [here](https://github.com/boa-dev/temporal/blob/main/src/builtins/core/instant.rs#L239). It should be implemented according to the [specification](https://tc39.es/proposal-temporal/#sec-temporal.instant.prototype.tozoneddatetimeiso). The method may need to be adjusted to be a `with_provider` API.
The method can be found here.
It should be implemented according to the specification.
The method may need to be adjusted to be a
with_providerAPI.