Code Ocean DOIs are a combination of two things: the prefix
10.24433/CO. , and the capsule ID on Code Ocean, e.g. https://doi.org/10.24433/CO.0a812d9b-0ff3-4eb7-825f-76d3cd049a43. A published capsule's DOI is available in its metadata page, under the Basic Info section. This field will be auto-populated upon publication.
If you need to know the future DOI for your capsule ahead of publication, you can find out the capsule ID from its URL – it's the portion following the word "capsule."
A DOI will not link to code until after publication.