You may see a Disclaimer that this activity is for advanced users and may fall outside the realm of Bytique support. Bytique offers limited support for advanced activities. However, this is rarely a problem and the supplier of the HTML snippet can also support you. Usually, this is just Copy and Paste.
Copy and paste or enter the code you want to use in the Custom Code field. The Title field is optional. In the example, we've added an example iframe widget for YouTube.
TripAdvisor is one common source of HTML iframe code. If you have a TripAdvisor account, or you want to claim your business there, go to https://www.tripadvisor.com/Widgets.