Nik Collection now asking me to Demo / Buy

I have just got a new Imac and have installed Photoshop 2023 on it. When I select the Nik Collection, a six-sided window pops up telling me I have 15 days trial left and a Buy and Demo button. I have been using the Nik Collection for years on my old computer with no problems, in fact it still works perfectly on my old computer. 

How can I get the Nik Collection to work on my new computer, please?