How long does it take to bridge from Polygon to Ethereum?

Could you please elaborate on the estimated time frame for bridging assets from Polygon to Ethereum? I'm curious to know if the process is instantaneous or if there's a specific duration that users can expect, given the current state of the blockchain networks and any potential congestion factors. Additionally, are there any steps or requirements that need to be fulfilled prior to initiating the bridge, and do they contribute to the overall duration?