CSS grid, flex box, fetch API

I fetched the data from the data.json file provided. It turns out that the timetracking cards I have rendered via javascript from the json file are only accessible when using css but when I use javascript "querySelector" I cannot access the elements. I started debugging and realised its because I used innerHTML, hence the elements are in form of a string thus I cannot access them via javascript. I hope I dont look like a help vampire, I really need to figure this out so that a user can be able to view the daily, weekly and monthly data dynamically. Thanks in advance