Hello or good evening! I am new to hexen in speedrun, my problem is that I do not know at all how to install Cryspy doom for hexen someone could help me if there is a particular link to take thanks in advance !

does crispy even support hexen in the first place??

Yeah there is Crispy Hexen which I used in my runs but it doesnt let you bind all items so I would recommend this sourceport instead https://github.com/jnechaevsky/russian-doom/ you will need to get hexen.wad and put it in the russian hexen folder, run the setup file to change your settings and you should be ready to go, if you need more information theres a readme file in the documents folder