I\'ve seen some questions and answers about custom events for firebase analytics, but i just wanted to ask you a straight question so you can give me a straight answer :)
If you are still looking for answer, You need to add custom parameters into the event manually once in the dashboard Like this https://support.google.com/firebase/answer/7397304?hl=en&ref_topic=6317489 Actually there is no need to link BigQuery for this. But it will take several hours to show up custom parameter once you navigate inside the event.