I have a real-time application running on my Raspberry Pi 3 B+ who generate a (very big) logs file. To allow non-technical people to download it, I create a Desktop application coded with Electron (NodeJs). 
The idea is to list all available IP addresses of the network with theirs hostname to allow the non-technical guys to select the correct one and automatically copy (through SFTP) the log file on their PC.
The SFTP code works fine (thanks to the module ssh2 in nodejs), however, I can identify as I would like my Raspberry. They correctly get IP address from the DHCP server, but I can't find a way to get their hostname.
Below the output from my code who list of available system on the network:

```
192.168.5.61  // err:  { Error: getnameinfo ENOTFOUND 192.168.5.61
    at GetNameInfoReqWrap.onlookupservice [as oncomplete] (dns.js:159:26)
  errno: 'ENOTFOUND',
  code: 'ENOTFOUND',
  syscall: 'getnameinfo',
  hostname: '192.168.5.61' }
192.168.5.61  //  undefined  //  undefined
192.168.5.65  //  USER-PC  //  ssh
192.168.5.62  //  KM59CD4F  //  ssh
192.168.5.100  //  server.blabla.com.au  //  ssh

```

As you can see, all systems send back a valid hostname, except for mine who raised an error. My question is, **who can I configure on my Raspberry to send back a valid hostname ?**
I tried to play with dhcpd.conf, dnsmasq.conf and hosts. The perfect result will be the same than '192.168.5.65 // USER-PC // ssh', with USER-PC becoming my system hostname.

Nota: When I put a static IP address in /etc/hosts, my code detect it and send me back the correct hostname.