Welcome @Mutale Happy you are here
It is good practice to search the forum before opening a new topic. See if this helps Server Error (500) - No Access To 8090 Panel - #22 by josephgodwinke | Search results for '500 error status:solved' - CyberPanel Community
Also it might be the client:
- Clear browser history e.g. in chrome Settings > Privacy and Security > Clear Browsing Data
- Disable Antivirus or proxy
- Flush your dns cache
- Change your dns servers The Best Free and Public DNS Servers (April 2023)