Adding items to a relation on collection/doc update

Hello all! I'm currently making a custom endpoint on a collection where I want to add a document to a relation.

      handler: async (req, res, next) => {
        const { applicantId, positionId } = req.body;
        console.log(applicantId, positionId);

        try {
          const position = await req.payload.findByID({
            collection: "job-positions",
            id: positionId,
          });

          let updateApplicants = [...position.applicants, applicantId];

          const doUpdate = await req.payload.update({
            collection: "job-positions",
            id: positionId,
            data: {
              applicants: updateApplicants,
            },
          });

          res.status(200).json({
            ok: true,
          });
        } catch (error) {
          res.status(400).json({
            ok: false,
            error: "Error while applying for position.",
          });
        }
      },

Job Positions has an 'applicants' field which should store the id's of Applicants that apply. When updating the position, I get an error

What is the correct way to do this?

Thanks!!

I can see in the JSON that the relation field gets populated with the whole record. Ideally it would only store the ID, right?

Bump 🙂 @jacobsfletch @alessiogr any ideas what I'm doing wrong here?