Q.Brown Spots On Angel Trumpet Flowers
I have brown colored decay spots on the angel trumpet flowers as they are blooming. I now notice the spots on the flowers before they open. The angel trumpet is in the ground and has been a healthy blooming plant for a couple years. The leaves are full and no spots on them.

Certified GKH Gardening Expert
It could be botrytis blight, a fungal disease. Thrips also attack buds. These articles should help:
https://www.gardeningknowhow.com/plant-problems/disease/treating-botrytis-blight.htm
https://www.gardeningknowhow.com/ornamental/trees/brugmansia/brugmansia-problems.htm