Creating unique ID's in bulk

Raydris the way you describe it doesn't seem to me to be efficient and is prone to error. And surely it means that in your flow you are going to need 99 "create item" actions! Not a good idea although you could set the flow concurrency to 1 to reduce that risk of error.

If I was doing this I would have a separate list for each user so that when a new item is added for that user it is automatically sequential (for that user) because of the ID.

Then I'd build a Power Apps front end that gets the items assigned to that user (based on their M365 login) in a gallery, they can add new items etc. You could then have a screen or a flow that grabs all the assigned items from each list and puts it into an email or a separate "master" list.

Rob
Los Gallardos
Intranet, SharePoint and Power Platform Manager (and classic 1967 Morris Traveller driver)