How i can validate the following function in Nodejs, express (REST API)

Question

How i can apply validation on the following field (MobileNumber) to check it weather it present in Database or not (Nodejs, Express ) REST API

  async  function  getUserByMobileNumber(MobileNumber) {
      try {
        let  pool = await  sql.connect(config);
        let  product = await  pool.request()
        .input('input_parameter', sql.VarChar, MobileNumber)
        .query("SELECT * from Users where Mobile = @input_parameter");
        return  product.recordsets;
      }
      catch (error) {
        console.log("Error found !! ", 404);
      }
    }