Mongodb server selection error: connection monitor closed

MongoServerSelectionError: connection to ******* closed. The day I installed mongodb I added IP address, database user, connection type: mongodb shell, mongosh, run using cmd. It was working fine, but since then this is the error I'm getting: MongoServerSelectionError: connection <monitor> to ******* closed. whenever I try to connect.I run connection string, type my password and then this error: MongoServerSelectionError. How to resolve?