Of the spell kits online, they are often quite similar to each other. When I was first starting out, I purchased one. It's a basic candle spell: a ritual cleansing, embue your intent in the candle, and the included charm, light thw candle and focus on your intent.
You coild do the same, finding a candle of a color which corresponds in your opinion with reconciliation, or whatever factor you believe necessary to bring back your ex.
Of course you may also opt for something a bit more complex, perhaps involving a honey jar to sweeten the other person's feelings for you, and also something involving a sigil, written petition, perhaps incorporation of any deities you follow or amy you may not but wish to ask for aid.
Your options are nigh limitless when it comes to creating your own magic work.