Hi @Wolfe, Thomas ,
You can inject the following JS code to a SharePoint Online page. You can copy it from the attached RedrictPageJS.txt.
Once you save the page and refresh it will redirect. See my demonstration.
You can use the modern script editor web part to inject the JS code: https://github.com/pnp/sp-dev-fx-webparts/tree/main/samples/react-script-editor. Take a reference to this article on how to deploy the web part to your SharePoint Online site: SharePoint | Online | Best Practice | install Modern Script Editor Web Part for SharePoint Online Modern Site.
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