Restarting Nextcloud after rebooting raspberry pi

I followed this video and downloaded nextcloud on my raspberry pi 4, it was working great
The command to start nextcloud was - docker run --name postgres -v /home/pi/nextcloud-db:/var/lib/postgresql/data -e POSTGRES_PASSWORD=234567 --network nextcloud-net -d postgres

This command was used in video to start nextcloud 1st time, now after I rebooted my raspberry pi 4, and run the same command and go to 192.168.x.y (dashboard of nextcloud) it says -

Internal Server Error The server encountered an internal error and was unable to complete your request. Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report. More details can be found in the server log. Nextcloud