Firstly, make sure Java 8 is installed. Java 17 or 21 should work as well but Java 8 is what I recommend.

Now, download this version of CraftBukkit and this version of AuthMe Unfortunately I couldn't get Canyon to work.

Now, make a folder, and put the CraftBukkit jar in the folder. Then, in that folder, make a folder named plugins, and move the AuthMe jar into that folder.

Now run the CraftBukkit jar like usual (using a batch file or java -jar). You won't be able to connect to it yet.

Now quit the server when it has finished generating the chunks (such as via sending the stop command).

Now open the server.properties file, and turn off online mode, and allow flying (AuthMe sometimes triggers the [very primitive] flying detection).

Now run the server again, and you should be good to go!