I have created a Minecraft server, and I would like to increase the maximum level of the abilities, by this I mean that instead of the speed being a maximum level 5, convert it to maximum level 25. I have been trying to change it to the .cfg file on the server, but I have not achieved anything

You can modify abilities (including max level) via datapacks, as explained here: https://github.com/CyclopsMC/EverlastingAbilities/wiki/Ability-datapacks

GitHub

Ability datapacks

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