Hi @Daniel_Chupe-O_Hanlo , welcome to the Asana Community Forum!
We have a thread about this topic in the #productfeedback category, you can see more information in upvote for the feature to manage forms settings here:
As it stands, it is not possible to manage Forms permissions, but this is certainly something our team will evaluate for future updates!
In the meantime, if your project is private to project members , and if none of the members share the Form link externally, nobody else will be able to access the Form! I know this is not ideal, but thought it could be useful until our team comes up with a better solution!
If you have more questions I suggest you to contact our support team .