SF_14.3 - https://www.progress.com/documentation/sitefinity-cms/pages-and-templates-api/pages-operations

CreateAPageRedirectExternal.json

{
	"Title":"My page",
	"UrlName":"my-page",
	"PageType":"Redirect",
	"RedirectPage": 
	{
		"RedirectUrl": "https://www.progress.com/sitefinity-cms"
	}
}