can not select my input type checkbox to do some work with them

Im creating a project of crypto using jQuery. I created a bunch of cards using $("#div'sId").append inside for loop. each toggle button (input type=checkbox) have the same id name + a specific index number he got from the for loop.

Im trying to do 2 things:

1. limit the selected checkboxes to 5
2. send the specific index number of each selected checkbox to send data to another function

I tried to select the checkboxes id, class, and even [input type=checkbox] without any success.

Html (inside the JavaScript)-

for (let index = 0; index < coins.length; index++) {
    $("#mainDiv").append(
<div class="form-check form-switch position-absolute end-0" style="transform: translateY(-35px);">
                              <input
                                class="form-check-input"
                                type="checkbox"
                                role="switch"
                                id="flexSwitchCheckChecked${index}"
                                style="background-color: rgb(62,138,152); border:rgb(5,19,20);"
                              />
                              <label
                                class="form-check-label"
                                for="flexSwitchCheckChecked"
                              ></label>
                            </div>

})

                                  how can I do it?

**There are other elements inside the .append function but they are not relevant