I had the who day trying to resolve cyberpanel 503 error

I have follows all the instances on Oracle free tier to install cyberpanel but in all 5 times instances, I have been getting 503 Service Unavailable The server is temporarily busy, try again later!
I followed how to the letter in your website but I have not been successfull.

Please share your server complete details os and all

Thanks for your response, I have resolved the issue was I was using ubuntu 20.4 minimal install that’s why I kept getting 503 not available.

I am getting same issue after 3 fresh installations.