Configuration of OPAC header has moved to Tools > News section since the release of Koha version 20.05. Earlier the configuration was at Administration > Global System Preferences > OPAC > opacheader. Follow the steps mentioned below to display a banner with Koha version 20.05.
1. Prepare a banner and place in /usr/share/koha/opac/htdocs.
Apply the following command to copy the banner in the home folder to /usr/share/koha/opac/htdocs.
sudo cp header.jpg /usr/share/koha/opac/htdocs
Replace the image name. Check the banner successfully copied to the destination.
2. Add an entry for OPAC banner in Koha.
Open Tools > News > New entry
Select Display location > opacheader (en)
Enter other details
Add banner image details. Select image option from the formatting toolbar.
Add image location details.
Give image with the address. Give localhost address (http://127.0.1.1/header.jpg) for Koha installation in a stand-alone computer. Give an IP address (e.g. http://192.168.1.1/header.jpg) with the banner image for Koha installation in a network. Save the image details.