SSL Communication Problem with custom S3 Bucket

[MHoyer44]

Hello,
I got an error if I try to connect to a S3 Bucket from our Storage Infrastructure.

{"Timestamp":1591716757156000000,"Logger":"FirefoxSend","Type":"send.upload.upload","Severity":2,"Pid":3572,"EnvVersion":"2.0","Fields":{"error":"NetworkingError: unable to verify the first certificate","stack":"\n at TLSSocket.onConnectSecure (_tls_wrap.js:1088:34)\n at TLSSocket.emit (events.js:198:13)\n at TLSSocket.EventEmitter.emit (domain.js:448:20)\n at TLSSocket._finishInit (_tls_wrap.js:666:8)"}}

I guess it's a problem concerning the CA certificates. Could you please help me how you set up an https connection in your application. I am new to express and don't know where and how to step in.