In order to export the watchlist, you need to click the Advanced view button in the right toolbar:
In the appeared dialog box, find the table with quotes and click the Export list button:
To import, click on the name of the watchlist in the right toolbar and select the Import list… function from the menu:
Please note that the input file must be in the .txt format and symbols should have the exchange prefix and comma separated (the same as seen in the output file):