👻 Customizing a Ghost(.org) theme, having trouble with fonts 🤦

Let me start off by saying that I barely know what I’m doing here: I’m taking over a web page from someone who can’t maintain it anymore. It’s currently using WordPress(.org), for, I guess, CMS, but after doing some research, I really liked the look of Ghost, and so I’m trying to recreate the current page there, though I don’t expect it to look identical by any means (hopefully it will look better!) There’s a free Ghost theme that I like, but it needs some tweaking to make it the way I want it. To start with, I would like the entire site to use the Palatino Linotype font, or a very close relative like URW Palladio, Tex Gyre Pagella, etc. The folks on Ghost seem to want me to use Google Fonts, which I would rather avoid at all costs (because Google), but it also doesn’t have the font I want (the WordPress site displays Palatino with no problems).

Anyway, I downloaded Palatino.ttf from somewhere, downloaded my Ghost theme in a zip file, unzipped it, and placed the ttf file in assets/fonts/, rezipped, and uploaded. But now the page seems to be using a fallback font and definitely not Palatino. Using the the web developer tools on Firefox, I get the following error messages:

downloadable font: overlapping tables (font-family: “Palatino” style:normal weight:400 stretch:100 src index:3) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: rejected by sanitizer (font-family: “Palatino” style:normal weight:400 stretch:100 src index:3) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: no supported format found (font-family: “Palatino” style:normal weight:400 stretch:100 src index:5) source: (end of source list)

downloadable font: overlapping tables (font-family: “Palatino” style:normal weight:400 stretch:100 src index:1) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: rejected by sanitizer (font-family: “Palatino” style:normal weight:400 stretch:100 src index:1) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: overlapping tables (font-family: “Palatino” style:normal weight:400 stretch:100 src index:2) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: rejected by sanitizer (font-family: “Palatino” style:normal weight:400 stretch:100 src index:2) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: overlapping tables (font-family: “Palatino” style:normal weight:400 stretch:100 src index:3) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: rejected by sanitizer (font-family: “Palatino” style:normal weight:400 stretch:100 src index:3) source: hedgeswebpage.mymidnight.blog/…/Palatino.ttf

downloadable font: no supported format found (font-family: “Palatino” style:normal weight:400 stretch:100 src index:5) source: (end of source list)

So what am I doing wrong? Also, I noticed that Font Squirrel has Tex Gyre Pagella, but I can’t figure out if you can use fonts from there in the same way as with Google fonts. Any advice, guidance, or commiseration would be much appreciated. Also, I’m actually using Ghost on Midnight, as you can see by the (fake) URLs in the error messages, if that makes any difference (probably not!). Apologies for the written filibuster.