First Install Java JRE 18.104.22.168 as usual as the download from the Apps server to IE8 would not work – and just install the version required by default so you might need a different version
Then add your Apps server to IE8 security settings:
Lower the security setting to medium-low for Trusted Sites:
Allow pop-ups from the Apps server:
When you start the application for the first time you may get one or more warnings like this:
Just keep clicking run and it should work.
Note IE8 is not yet supported by Oracle.