I tried both ways (plugin and directly in font folder) and none of them works.
With this code in the additional CSS it seems to read the code (the h1 font changes) but that is not the font I loaded (my font name’s family is “wildone”, but this is not the style of the font)
I think there is an issue with how you load the fonts in the theme. Have you tried this plugin? https://ww.wp.xz.cn/plugins/olympus-google-fonts/ – I don’t think your font is available on Google fonts, but you may have to change to one that is available there to get it to work more easily.