Manually executing campaigns can be done at any moment from the campaign list.

It can be used for any campaign, even if its data source is not of manual type.

You will just have to provide a file with the data, submit it, and then you will be taken to the activity section where you can wait for the end of the execution.

Alternatively you can provide an email address where you'll get notified when the execution ends (nbt version > 1.5)