How to give domain name for IP and Port

Hi<br/>
<br/>
I am running a local python based flask app on my machine and I can access it using the url <URL url="http://192.168.1.21:5000">http://192.168.1.21:5000</URL>. I am using Draytek Vigor 2865 router and I want to give a domain name for the flask url but I didn't find any option to do this. So what I have done is I have given domain to the IP by going into Applications -> LAN DNS/DNS Forwarding so now I can access flask app using url <URL url="http://myapp.com:5000">http://myapp.com:5000</URL><br/>
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Is there anyway to include port number in the domain name as well so that instead of <URL url="http://myapp.com:5000">http://myapp.com:5000</URL>, I can directly access <URL url="http://myapp.com">http://myapp.com</URL><br/>
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Thanks

No, it doesn't work that way. You could deploy a Reverse Proxy like Nginx Proxy Manager. Point your hostname at that and have that proxy your traffic to IPAddress:Port