regions property
A complex type that contains one Region element for each region
from which you want Amazon Route 53 health checkers to check the specified
endpoint.
If you don't specify any regions, Route 53 health checkers automatically performs checks from all of the regions that are listed under Valid Values.
If you update a health check to remove a region that has been performing health checks, Route 53 will briefly continue to perform checks from that region to ensure that some health checkers are always checking the endpoint (for example, if you replace three regions with four different regions).
Implementation
final List<HealthCheckRegion>? regions;