Before we can fire events into your property, we need your GA4 Measurement ID, which can be found here. Note, you'll need to first have a GA4 property created on your side - Google has some pretty easy to follow guides in the UI to help you get setup if you don't have one yet.
Admin > Property Settings > Data Streams > Data Stream Details > Measurement ID (will begin with 'G-')
Note: Roadster currently supports passing data into 4 measurement ids. You shouldn't need to pass data into more than 4 properties, nor do we recommend that as it can get confusing and messy to maintain overtime.