How to write data in a subcollection? Firebase React

Question

I wish to be able to add projects in a subcollection called projects. Currently my tree is: db/membres/[membreID]/projects/(here I want project ID that firebase generates)/(information of project) Here is my firebase:

here's what i've tried:

This is the error I get: Invalid document reference. Document references must have an even number of segments, but membres/UVLPL9kxP1hGuiwCStS4oDLJvxo1/projets has 3.

Answer 1

The error message is quite clear: you are trying to write to a document at path /membres/$uid/projects , but that is the path of a collection.

If you want to add a document to that subcollection, use addDoc instead of setDoc .

Answer 2

addDoc works like that:

addDoc(CollectionReference //i.e collection(db, "path"), element)