Hello Jacychua,
You can find the 12 May 2020 patch for KB4551853 (May 12, 2020—KB4551853 (OS Build 17763.1217)) in the below link,
https://support.microsoft.com/en-us/topic/may-12-2020-kb4551853-os-build-17763-1217-c2ea33f7-4506-dd13-2739-d9c7bb80b26d
Before installing this update
Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
If you are using Windows Update, the latest SSU (KB4549947) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.
Hope this answers all your queries, if not please do repost back.
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