Shai Masot did NOT offer Joan Ryan £1 million as some kind of bribe. The context surrounding this segment of the Al Jazeera investigation, including Joan Ryan discussing names put into the embassy, is around funding trips to Israel.
People involved in advocacy for a particular cause are often able to meet with politicians in order to lobby them.
It isn’t at all unusual for foreign embassies to employ lobbyists to operate in the UK parliament. It’s a standard practice.