The following code will use a value from the url querystring. There are various ways to pick it up, but we recommend the cross-platform API which works in Dnn and Oqtane.

1. Pro mode Cross-Platform (Dnn and Oqtane): @MyPage.Parameters["id"]
2. Older mode Cross-Platform (Dnn and Oqtane): @CmsContext.Page.Parameters["id"]
3. This would only work in Dnn: @Request.QueryString["id"]

Usually you would have somepagename?id=27 in the url, and then using @MyPage.Parameters["id"] / @CmsContext.Page.Parameters["id"] you would pick it up.
But with DNN, there is an additional processing that happens, as DNN tries to create nice URLs resulting in somepagename/id/27. But on the server, this is still treated as the ?id=27, so you still use the same method to access it.