I found this on the IG page which says that it should open a position, I have not got one open on my account however. Not sure if anyone has had it appear?
https://www.ig.com/uk/help-and-support/spread-betting-and-cfds/market-details/what-happens-to-my-shares-position-if-the-company-offers-a-right#:~:text=If you have an open,take advantage of the offer.&text=Take the rights up by,team prior to the deadline