Hi there normally support is given on the discord but here is the answer turn killbelow0 in the config to false and the death is fixed :) and Respawnhandler to false if u have your own respawn handler to solve the respawning
Item ID's are removed way long time ago we use material names now : https://hub.spigotmc.org/javadocs/bukkit/org/bukkit/Material.html

Hope this helps thanks for your review

now you have it :) have fun!~
(ps. The reason is Paypal. since im not a company but a hobbyist they are forcing me to quit selling or i lose my paypal so thats why