back office wordpress

Hello,

2 small questions:

1/ is there a way to block on the back office of wordpress, the fact of being able to play only 1 time in each game

I blocked it via the front via a wordpress page but some smart people found the technique to cheat

2/ I wanted to create an additional role so that certain people can access all the results with a personalized role

I added these roles to a basic role but it does not work, I went to the plugin settings to see if there was a setting but I found nothing

Thanking you in advance for your help