First, I do not think anything that I am doing is against the guidelines but if it is, my apologies - let me know and I will do my best to fix whatever the problem is.

So I am here to ask if there is a way to deal damage and add your spellcasting ability modifier or any ability modifier. Specifically, I am attempting to recreate RPGbot's Way of the Sun Soul revisions for my private game, even more specifically his changes to Searing Sunburst, "Change the base damage to 2d6+Wisdom Modifier." I  cannot seem to figure out how to do this and I am uncertain if that is because I literally cannot do it OR if I am just missing something. Currently I have created a spell which I have attached to an item which I will give to any (revised) Sun Soul monks. But I am curious if there is a cleaner/better method.

Thank you all for your help.

Link to where they go over the changes: https://rpgbot.net/dnd5/characters/classes/monk/subclasses/

You need neither a spell, nor an item. Just create and “Action” and attach it to the Subclass Feature, make the action a “Spell Action,”  set the Ability to Wisdom, the dice count to 2, the die type to d6, and away you go.

Thank you very much for your help, I really appreciate it.