Error mongodb connection

1 week ago, I deployed ocean digital application. there wasn’t any trouble and could do normally. but, yesterday I got something trouble. I thought that error was in database mongodb connection. this is the error

I think that host and port connection already right. who has solution about my problem?
thank you.

deployed using what?
where you host your mongo ?

i’m using mup, in digital ocean

I would check if that database is running .
As I am using mupx I dont know exactly how u can do it in mup configuration.
Try typing “mongo” on DO so it try to connect to default mongo port? or something like that.

Any chance I could hire you through freelancer.com to help me with developing a hardcore app? I’m a noob.