How would I synthesize ethyl 2‐oxocyclohexane‐1‐carboxylate from cyclohexanone?
As you will see if you look at the reference mentioned by @Mathew-Mahindaratne,   the standard conditions for this transformation is NaH/KH in THF at reflux with diethyl carbonate (EtOCOOEt) with an acetic acid workup.

The Organic Syntheses procedure here uses dimethyl carbonate, but will be equally applicable for diethyl carbonate.