https://www.yoyogames.com/studio/download
GameMaker Studio Standard is now completely free. This version of the popular 2D game development engine previously cost $49.99 and removed various limitations on the trial version of GameMaker Studio. The previous limited trial version has now been retired.
The first line of text on the page that you've provided the link for is this:
"The GameMaker: Studio™ installer can be used in a resource-limited trial mode, or you can enter a valid Standard, Professional or Master Collection licence key to access the full features available.
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