I can’t enable blood oxygen on my watch

When I want use the blood oxygen level app on my watch it says that I should open the apple watch app on my iPhone then it says I should enable the blood oxygen level and when tab that, it says it says an unknown error occurred when completing your setup unable to proceed. I have looked everywhere for a solution but i found nothing. Blood oxygen level app is available in my region though, I have also tried resetting my watch and non of that worked. Please, help!