Use revenue account in general journal

Hi Everybody, 

I would like to use a revenue account avalaible in my project group to post revenue within my general ledger > journal entries > general journal. 

My process below  :

- Creating a voucher in General ledger > Journal Entries > General Journal 

- Choosing a account type = project

- Selecting my category 

- Posting

If I have a credit revenue to post, i want to use the revenue account available in my project categories. 

The problem is, each time i'm trying to do it, the system is looking for my cost account and not revenue account either if the amount  is on the credit of my voucher. 

I must miss a setting to use the revenue account of my category in my general journal, but i don't know it yet, does someone have an idea? 

Thanks for your help

Best regards