Although this was not really the solution, I was able to debug my application thanks to your suggestion of using the Docker desktop application.
What I did was:
Firstly, I copied the the steps here (the answer was already in my face…) and then did some tweaks on my Qovery Application.
In the settings of my application i added a Port 80 (make sure to set it to public), because in the Dockerfile there is an EXPOSE 80 so I copied the number. (unable to show image because I can only put one 
)
Lastly, I configured my Build mode and Dockerfile path showed in the image below.
If anyone is interested to look on the src files just go back to my first post here there is a github link.
Additional resource for those who are new to Docker just like me:
Docker & React
I only followed up until Building our image then used the codes in my previous link (angular-app-deploy) because this one has Dockerfile codes for making production ready files which is important when deploying.