For anyone having this issue, here was the solution ie. Add the Attributes embed script after running your code to add incremented attribute values.
<script>
window.onload = function() {
// Select the parent element
let parent = document.querySelector('.team-list_list');
// Select all the child elements
let items = parent.querySelectorAll('.team-list_lightbox-item');
// Iterate over each item
items.forEach((item, index) => {
// We increment the index because it starts from 0
let counter = index + 1;
// Find the specific child elements within each item where you want to apply the attributes
let buttonElement = item.querySelector('.team-list_modal-2_button');
let coverElement = item.querySelector('.team-list_modal-2_cover');
let popupElement = item.querySelector('.team-list_modal-2_popup');
let closeElement = item.querySelector('.team-list_modal-2_close');
// Add the attribute to the target elements
if (buttonElement) buttonElement.setAttribute('fs-modal-element', `open-${counter}`);
if (coverElement) coverElement.setAttribute('fs-modal-element', `close-${counter}`);
if (closeElement) closeElement.setAttribute('fs-modal-element', `modal-${counter}`);
if (popupElement) popupElement.setAttribute('fs-modal-element', `close-${counter}`);
});
//[Finsweet Attributes] Modal
(()=>{var t="https://cdn.jsdelivr.net/npm/@finsweet/attributes-modal@1/modal.js",e=document.querySelector(`script[src="${t}"]`);e||(e=document.createElement("script"),e.async=!0,e.src=t,document.head.append(e));})();
}
</script>