tiěchǔchéngzhēn
ㄊㄧㄝˇ ㄔㄨˇ ㄔㄥˊ ㄓㄣ
Simplified 铁杵成针
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
Keep 鐵杵成針 and it comes back until you know it.