Hi @sunaina j thanks for posting in the Lucid community!

Anytime you import issues from Jira into Lucidspark cards it will import any/all selected issues even if they already exist on the board. To stop this you will need to select only issues that you would like to have a new Lucidspark card created for skipping anything that has already been imported. If there are duplicate cards in your board already unfortunately you will need to manually remove those. You can use the keyboard shortcut Control/Cmd + F to search for any duplicate cards you have with the same title.
 
If you'd like to suggest automatically skipping import for cards that already exist on the board as a feature improvement please add your idea to our feature request form. Ideas submitted to this form are passed on to the product development team for their consideration.

I hope this helps! Feel free to comment below if you have any other questions or comments.