It doesn't need anything special. In fact it would be happy in poorish to moderately fertile soil so a general purpose compost would be fine. It likes free draining soil so you could mix in some vermiculite or similar to the compost with broken terracotta pots or similar in the base to also assist drainage.
Position full sun or part shade and as with any new plant , lots of water especially in the early days to settle it in.
An attractive hebe. Good luck with it.

I would give it some shelter in the winter. Mine went horribly straggly and was a mess even when I cut it back. It had to go in the end.

Hebe Heartbreaker is one of the least hardy varieties. Certainly needs to be in a very sheltered, sunny, free-draining spot or in a container. Don't be surprised if you loose it in a cold, wet winter.