Training requirements to fly circle-to-land approach
 

From the Embraer 145 Procedures Manual:

First Officers are allowed to fly circle-to-land procedures in marginal
weather they must be trained to do so proficiently. The usage of the
autopilot on Circle-to-land approaches is recommended.

Does anyone know an official reference (e.g. EU-OPS) where it states any training requirements to conduct circling approaches? I couldn't find anything. Many thanks!