Illuminated flashers

Hello. In movies from the USA you can often see that the turn signals also shine when the light is on. I have two questions: 1. How can you connect this so that the turn signals can turn on with the standlight, but still when the turn is still possible? 2. Actually this is not allowed, but I have read that light yellow fog lights are allowed, if they only go on together with the normal lighting and are not higher than the turn-off light. has a nice Tüv tester, who enters the luminous turn signals as light yellow fog lights, wouldn’t it be allowed?