On a schedule the scenario pulls fresh contacts from Bitrix24 and pushes them into Vk customer lists. Retargeting always runs on a current base.
Automating Bitrix24 and Vk takes no code: a ready-made scenario does the routine for you.
You can launch this Bitrix24 + Vk integration in Scriptera: describe the task in plain words — the scenario is built, launched and monitored for you.