If your company is treating you to lunch, you will not be asked to enter your credit card. Be sure to use the group lunch link that your lunch organizer sent (via email or Slack). You may also access the lunch from your calendar. As long as you use your group lunch link, you will automatically be added to the group order.
You will only be asked to enter credit card information if your company is contributing $x per person and if your order total (including tax) exceeds this $x. In this case, you will only pay for the difference above $x.
If your company limit is $15 but your dish total (including tax) is $17, you will be asked to enter your credit card and you will be only charged $2.