So I am currently playing a cleric in a Curse of Strahd campaign and after talking about how things have been going with my cleric and how I have been doing story-based leveling decisions my DM asked me if I would like to take any paladin levels and he would let me use wisdom as my spell casting stat.  Because of story etc this would actually be awesome.  I have been using D&D beyond this whole time to manage my character but I can't easily see a way to facilitate this change on here, so before I go to pen and paper for the rest of the campaign I thought I would ask here if there is a way in app that I could do this. 

Edit: I realised I should add that currently my charisma is 11 so I cant make a subclass that uses wisdom as a homebrew because i can not select paladin without char 13 to get to that subclass. 

Don’t think so. 

Regarding your second point, you can disable multiclassing prerequisites on the character so they can use a homebrewed subclass with WIS as the casting stat. I'm not a homebrew wizard, so you may want to post this in the Homebrewing section for help actually making the subclass. But I know you can disable the multiclassing prereqs in the character sheet to be able to take that level in Paladin.

Thanks guys, I might go to the homebrew section,  though I just thought about making a subclass that gives me -1 to all charisma skills and then edit my cha to 13 and the math should work out in the end.

Edit: I realised I should add that currently my charisma is 11 so I cant make a subclass that uses wisdom as a homebrew because i can not select paladin without char 13 to get to that subclass. 

 If you're just talking about a DnD Beyond restriction in the character creator, that's very easy to get around by just setting your charisma to 13, selecting your new multi-class, and then setting charisma back to 11.  It only ever checks the one time when you first add the Multi-class.  Only use this if it's DM-approved though and you just need a hack to cheat your way past the website restriction

Quote from DrJawaPhD >>

Edit: I realised I should add that currently my charisma is 11 so I cant make a subclass that uses wisdom as a homebrew because i can not select paladin without char 13 to get to that subclass. 

 If you're just talking about a DnD Beyond restriction in the character creator, that's very easy to get around by just setting your charisma to 13, selecting your new multi-class, and then setting charisma back to 11.  It only ever checks the one time when you first add the Multi-class.  Only use this if it's DM-approved though and you just need a hack to cheat your way past the website restriction

 You can turn off the multi class requirements. 

You would have to make a homebrewed version of your subclass and enter “Wis” as the spell casting stat under Basic Information. Unfortunately it won’t actually kick in until you take your 3rd level of paladin and actually choose that subclass.