onLoad() {
 uni.loadFontFace({
        global: true,
        family: 'font-din',
        source: 'url("https://xxx.cn/xxx/D-DIN-Bold.ttf")',
        success() {
      	  console.log('success')
        }
  })
 },
uni.scss:

  @font-face {
   font-family: 'font-din';
   src: url("https://xxx.cn/xxx/D-DIN-Bold.ttf")
  
  }
<style>
font-family: 'font-din' !important;
</style>

调试基础库：2.32.0 ；
oppo find X3 PRO  V12.1