Hi,
We are having an event where people can register via a form to it and pick a time. We need to be able to have that time populate in an add to calendar link. We normally use a calendar file but how can we do that when multiple times can be chosen?
How many different times are you talking about? I have trouble envisioning a fully-automated solution without a lot of developer work. It may be easier to enter them into a different flow based on the time they chose (and thus receive a different confirmation email with a different calendar link). But that would only be feasible if there's only a handful of times to choose from.
Just send an Agical link, with a {{lead.token}} for the date/time, instead of a Marketo ICS file. The Agical link simply serves up an ICS when clicked (or Google Calendar) and it's all dynamically created from tokens, like: