Datapack Not loading on server

[Archive89]

I've tried checking the datapack format, restarting my server and it keeps not loading. I tried enabling the other part but it can't because of flags. Can someone help me?

[misode]

Did you follow the instructions on the readme? Do you have any mods installed?

[Archive89]

i think i did, could you provide some basic installation for me? and i do but there all fabric and mostly from masada. like litematica, itemscroller, etc etc

[THZoria]

Found new data pack file/1.21, but can't load it due to missing features minecraft:update_1_21
I did follow the guide ? :/