How to findAll by a specific variable in MongoDB?

I have the following MongoDB collection of bets:

{
        id: String,
        user_id: String,
        type: String,
        events: [{
            eventID: String,
            sport: String,
            evento: String,
            aposta: String,
            estado: String,
            odd: String
        }],
        total_odd: String,
        bet_ammount: String,
        state: String,
        date: String
  }

My goal is to send an HTTP request into /bet and reply with all the bets in my Database that correspond to the given "user_id" that is sent in the initial request.

For example, if there were 3 bets that had the user_id with "61e0eb548714ee662c2d76d1", I would want to to send all 3 bets in the body of the reply. I've had a similar request where I would only need to send a specific bet according to it's ID. The code for that is the following:

router.get('/bet', (req, res, next) => {
  let token = req.headers.token;
  jwt.verify(token, 'secretkey', (error, decoded) =>{
    if (error) return res.status(401).json({
      title: 'Unauthorized'
    })
    BetModel.findOne({ user_id: decoded.userId }, (error, bet) => {
      if (error) return console.log(error)
      return res.status(200).json({
        title: 'Bets Grabbed',
        bet:{
          _id: bet._id,
          events: bet.events,
          total_odd: bet.total_odd,
          bet_amount: bet.bet_amount,
          state: bet.state,
          date: bet.date,
          user_id: bet.user_id
        }
      })
    })
  })
});

How could I change this to initially get every bet for that specific user_id and then send them all in the HTTP reply?

You can create another route that changes the findOne query to find, and sends the result to the HTTP reply.

BetModel.find({ user_id: decoded.userId }, (error, bets) => {
     if (error) return console.log(error)
     return res.status(200).json({
          title: 'Bets Grabbed',
          bets: bets
     })
})

You could then iterate through each of the bets on the frontend.