Add page-anchored text, please

I would like to be able to add text to a page that is not anchored to a staff or system, but also not a part of the header or footer for every page. The specific examples: I like to add my website url to the footer of the last page only, and once the song is registered with CCLI, the CCLI number in the footer of the first page only. I don't really need either of those in the footer of every page. The only options to add text I see is to anchor it to either a system or staff, and if the music spacing changes, you never know where the text is going to end up. In fact, I've positioned text exactly where I want it, only to find it somewhere else on the page the next time I open the file, even though I've made no changes. If I upload a score to MuseScore.com, it also usually changes the spacing arbitrarily, so again, I never know where those two text items will end up. Maybe there's a way to do this I haven't found, but the previous notation software I used specifically had "page-anchored" text that stayed locked to a specific location on a page, regardless of the music and staff spacing on that page. Please add this feature, or tell me how to do it if it's already there.
Using MuseScore 3.0.5 on MacOS 10.13.6