Hello ​@PeterCarno 

this is currently not possible in the new interface of Slido however there is still an option to add Ideas in the old interface. Here is how you can switch to old interface for now:

After switching you can go to the settings/features and enable Ideas feature. That will allow you to create a topic and after activating it your participants can vote on the submissions. 

That’s perfect! This is what I was looking for! Many thanks!