An initiative is something specific you wish to assess against the JTBD and a set of business dimensions. An initiative is something the organisation is considering doing.
It might be micro: add x to our homepage. Or macro: outsource business function y, or acquire business z.
Usually, the organisation will have loads of these and prioritising them may be the end goal of the process. People are definitely not short of ideas and you'll be able to gather them from across the organisation. Customer suggestions are worth assessing if they haven't already been captured by the organisation.
Sometimes, however, specialist external partners might be able to suggest some initiatives that the organisation hadn't thought of. For example, "how about a [insert emerging technology x]".