If e-voting is currently being used, what type(s) of technology used?

General Elections Act 1991 (as amended in 2018)

71. (1) Each voter shall have one transferable vote.

(2) A voter, in recording his vote:

(a) must place on his ballot paper the figure 1 against the name of the candidate for whom he votes; and

(b) may in addition indicate the order of his choice or preference for as many other candidates as he pleases by placing against their respective names the figure 2, 3, 4, 5 and 6 and so on in consecutive numerical order. […]