pr_average and pr_last shown as invalid column names

Hello, for DSY.PA I tried to get the stock price, but the columns were called invalid. Here is the link: https://api.roic.ai/v1/rql?query=get(pr_average())%20for('DSY.PA')&showdates=true&showheaders=true&transpose=true&apikey=2b45d6f194194b69b517760c78e71e1b

Best regards,

Vlad