External Client user and access to Project documents

External Client user and access to Project documents

Hi there- 
I have added external client users to my project and have configured settings in Issues for them. My issue now is I don't want external users to have view/read/edit access to any documents or folders. 

I want them to have access to only one particular folder. How to do this? I don't see this in FAQ section. Please advise. 


Thanks
Maria