If you are trying to play on the Minecraft server hosted at minecraft.touhou.ca you will need the following:

Once you have the zipped modpack downloaded, install it in your launcher of choice. In Prism / PolyMC, this is done by adding an instance and "Import from ZIP". Then launch the instance and add the server "minecraft.touhou.ca"

Contact me by whatever means you know how with your username and I will add you to the allow list. Then simply connect by entering 'minecraft.touhou.ca' in the server address box. Your launcher may tell you that you have an incompatible modlist, but this is probably fine. If it doesn't work, let me know.

Your game might tell you that a minimap is outdated; don't worry about it.