Function $url

$url(key: string, def?: string): string
Retrieves a URL string from an environment variable and validates it's a valid URL.
Parameters
- key: string
  The name of the environment variable
- Optionaldef: string
  Optional default URL string to use if the environment variable is not set
Returns string
The validated URL string from the environment variable

Throws
Will throw an error if the URL is invalid, or if the environment variable is missing and no default is provided
- Defined in url.ts:10