Conditional Update Query is not working

Having a document like this. I would like to change the user’s avatar based on the id. for example if the ID matches fromUser’s ID I would like to change the avatar of that object only. but I’m new to mongo and my query is not working as expected.

await Conversation.updateMany(
 {
   $or: [
      { type: 'userMsg' },
      { 'participants.fromUser.id': userObject.id },
      { 'participants.toUser.id': userObject.id }]
   },
   { $set: { 'participants.user.avatar': avatar } },
);