Error cannot connect to mongodb

I’m trying to do a backup using Percona Backup for MongoDB everything is working properly

after i tried to run the following command and got the error

I am sure that all my information is correct, I have double checked.Here are some of my logs

Hi, it seems from the error that your replica set is not healthy. Have you checked there is a primary?

i checked and mongo is still working

Hi, are you running a replica set? from your output it seems it is a standalone node which is not supported by Percona Backup.