How to get Attachment Id when clicking a file in Attachments list in Freedom UI

I assume you could get it using the following (this works for lists, I assume it's the same for gallery mode)

const selectedId = await request.$context.TheListNameHere_ActiveRow;

See https://customerfx.com/article/responding-to-a-row-selected-event-in-a-creatio-freedom-ui-list/

Also, you could add the button/action as a menu item when you click the three-dots button, see https://customerfx.com/article/adding-row-action-menu-items-to-a-creatio-freedom-ui-list/ 

Ryan