1.) Stop your server
2.) In your server config file enable command block.
3.) Restart your server
4.) Use /give command to give yourself a command block then place it in the world.
5.) Proceed to place a red torch in the world then connect it to the command block with a redstone.
6.) Now you are ready to rclick the command block to then input the command such as the one below.
/pokemake Charmander @p
You can also do
/pokemake Charmander @p l:5