php - How to index custom url based on terms searched on Google -

sometimes see on google links terms searched on google parameter. example, if search "strangeword", can see in results:

example.com/p=strangeword 

i'm pretty sure generated automatically, how it? i'm using php nginx.

it isn't generated automatically. if page in index, it's because there crawlable link page - whether intentionally done webmaster or not - , google happened crawl link.

links can generated users sharing such page, bookmarking it, or linking own sites / social profiles