May I know what is the reason to occur this error it happens while the WordPress update
I faced this problem after the WP upgrade page timed out.
so used the following instructions to resolve it
Enabled debug to identify which plugin was causing the problem (in my case it was WP)
- https://profreehost.com/support/common-errors-and-issues/http-internal-server-error-500
General instruction to install such scripts manually - https://profreehost.com/support/files-and-directories/how-to-install-large-scripts-and-upload-big-files
& Detailed WP plugin’s manual installation page
Good luck!