Players can't use the items

If its the case that you already make your items, and want to test with a player without op, without perms, they try and receive this message:

That is because they don't have permissions to use the items, since nobody would like to give op to players, you have to give the correct permissions to your default players, for this, just check the section of Permissions, and read the Tip on the top of the page ^^

This image:

Just in case YES -> It is required to have a perms plugin to manage perms for items to the players.

If you DON'T HAVE A PERM PLUGIN and DON'T WANT TO ADD ONE the only way is giving op to your players, if you don't want that, just download a perm plugin

Discord

In case this didn't help you to achieve what you wanted or doesn't work for you, feel free to ask in the Discord of Ssomar plugins your question.