Welcome @Margarida_Ferreira to the UiPath Community Forums 
You are in the right place for help. The forums are a great place to learn and understand what other developers are doing 
Asking good questions will get you good answers!
Okay…let me try and answer your question now:
You can also take a look here at this post (I had the same question 
)
Capture Selector and convert to String Variable - Help / Studio - UiPath Community Forum
If you are still having trouble, open “Ui Explorer” from Studio. Indicate the element and paste the results back here?
From there we just need to find the relevant attribute’s name and insert this into the “Get Attribute” activity.
If you are still stuck, let me know
Cheers
Steve
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