Select what to do in case imported comments has the same ID as comments you have in the current opened prototype. Replace comments or add as new (copy).
Select a category for all the imported comments if needed and press 'Ok'.
If you want to refresh comments from a prototype you have previously published in your Justinmind account you can use the operation 'Refresh comments' that you will find in the Comments section toolbar. Once you selected the option perform the following steps:
Select what to do in case imported comments has the same ID as comments you have in the current opened prototype. Replace comments or add as new (copy).
Select a category for all the imported comments if needed and press 'Ok'.