MongoDB Primary and Standby Mode Replace Copy Mode

  mongodb, question

Ask the great god:
Now there is a Mongo library with two primary and backup nodes. If you want to replace it with a replica mode, is there any good plan to ensure that the incremental data of the primary and backup nodes are stably synchronized to the replica cluster? Or do you have any good information for reference?

Do you know about the official documents?
Convert a Master Slave Deployment to a Replica Set