Permisson to revoke account definition

Hi everyone,

we want to enable a role based permisson group to revoke the account definition of an ADs Account. 
We already tried to assign the task permission to the permisson group but it didnt work. (1. User Interface -> 2. Task definitions -> 3. RevokeAccountDef) 

The user in the permisson group cant see the task button at all. 


Thanks for your help