The certification was retired, as it happens to many others. It's not that you lost it or let is expire, it's just not active anymore in the current MS certification plan.
You can get more help over at the certifications forum, and maybe find your path forward:
Microsoft Training and Support: https://trainingsupport.microsoft.com/
Microsoft Certification - Exams: https://trainingsupport.microsoft.com/en-us/mcp/forum/mcp_exams