How to change the port for the npm run watch?

I am trying to watch the development using npm run watch. But it moved to http://localhost:3000 instead of http://localhost:8080. How to change this port 3000 to 8080? Because I am using the Tomcat server in 8080 port.

[BS] Proxying: http://localhost:8080
[BS] Access URLs:
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       Local: http://localhost:3000/server1/demo3/index.html
    External: http://192.168.126.1:3000/server1/demo3/index.html
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          UI: http://localhost:3001
 UI External: http://192.168.126.1:3001
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via K.Suthagar