how do i get the datapacks that open loader downloads, i want to download some of them

OpenLoader is primarily intended for sharing datapacks you make yourself as part of a modpack. CurseForge has this project category, however many of these projects are mislabled and are not actually datapacks.

The Vanilla Tweaks project has a pretty extensive list of datapacks they have made which should all be compatible with OpenLoader. There is also the Terralith pack which adds many new biomes to the game. I believe they have a few other packs on their website as well.