How to check if a value exists in Markdown markup when sending a Telegram bot message?

Question

JavaScript

Hello!
Forming the body of the message to be sent by the bot

let md = `
  game #_${data.game}_
  Раунд: ${body.event.roundInfo.name} (${body.event.roundInfo.round})
`;
 bot.sendMessage(chat_id, md, {parse_mode: 'Markdown'});

the values ​​are taken from the array, and if for example there is no such value ${body.event.roundInfo.name} in the array, the script will stop and an error will be thrown.
How can I check for these values ​​here? if they are not present, then do not display this line