FormData in policy file

Hi! How can I access FormData in a policy file? I’m trying to make that users can only update their avatar:

  module.exports = async (ctx, next) => {
  if (ctx.state.user != ctx.res.body.refId) {
    return await next();
  }
  ctx.unauthorized();
};

ctx.res.body and ctx.res.data return undefined.
I’ve also tried to check for user id in the Upload.js controller, but it doesn’t seem to have access to ctx as it returns undefined

have you ffixed this? i have the same problem