One of the methods of delivering your advertising message to your potential customers may be public events. These activities include both online and offline conferences, various trainings and other events that gather a lot of people in one place.
Often at such events, you can speak on a topic for free and sell your expertise, and at the end of the speech to make a special offer for the audience, hidden or openly selling any product.
Such events are a great opportunity to make a personalized offer to the audience, especially if the event is thematic. About your promotional offer you'd better talk to the event organizer in advance.
You can organize public events by attracting sponsors and speakers, then you can place your advertising message anywhere, as you are the organizer of the event.