Hi Alex,
Currently to add URL keywords you have to enter them through the Cart UI but as a possible solution, we could URL Keywords field to the Product Import so that you can enter the keywords in your spreadsheet then upload them all. To move forward and send this enhancement into development please purchase 2 Support Credits at the following link:
https://www.smith-consulting.com/pd/P...
Please let me know if you have any other questions.
Thanks