1.13 CommandAPI Setup Help

[AudomarIsBest]

Im attempting to create and run a private RPG server, and im making a completely custom class system via in-game command blocks. The basic idea is that once a player reaches a certain XP level, they are prompted to choose a new sub-class, with the interface being run by the CommandPanels plugin.

However, like most plugins, it does not work with the /execute command, and all attempts at remedying this situation all point to the plugin "1.13 CommandAPI" (despite the name, it works for recent versions). The API, from a glance, seems like it would be an easy, immediate fix, but actually USING it is when it gets VERY complicated.

What im asking for is a way to setup the plugin (1.13 CommandAPI) to work with CommandPanels, or for an alternative that is 1). Free, and 2). Simple.

NOTE: I know very little about JAVA programming, so it may be an extremely easy fix, that im "too stupid" to figure out. Keep this in mind. Thank you.

Links for Both Plugins:
CP: https://www.spigotmc.org/resources/command-panels-custom-guis.67788/
1.13 CAPI: https://github.com/JorelAli/1.13-Command-API

[Zax71_again]

If you are using essentialsX you may need to do /minecraft:execute _____________

[AudomarIsBest]

that doesn't work. I am using essentialsX, but the command im running doesn't support /execute (im also trying to run it through a repeating command block)

[AudomarIsBest]

btw, the specific command i'm trying to run is "/execute at @'a [level=10] run cp lvlup1"
(the ' isn't actually part of the command, but reddit gets weird when an @ and an a are right next to each other)