Question assigning DNS/ domain to a ip:port

[lopklopk]

Hi, anyone pls help me in assign ip in plesk (cent os 7 4 gb ram) to my instance installed at some port,
like http://103.228.113.43:5000/
here 103.228.113.43 is my Plesk ip, & my application installed at 5000 port (also at root folder location etc/thingsboard etc ) so finalled url of application is http://103.228.113.43:5000/ ,
i want to give it a domian name like slogfy.com / roboslog.in etc...
I know to connect domain but as this installation at not at Httdocs where I can map easily my domain to a httdocs or inside folders .
so i've difficulty to give it domain name. ,, pls help me or any reference url

Thanks