NO, it can’t !!!!!!
A will must be signed in accordance with the formalities set out in Sections 77 & 78 of the Succession Act, 1965.
Essentially, it states that no will shall be valid unless:
a) it is in writing, and signed by the testator, or by some other person in his presence and by his direction; and
b) it appears that the testator intended by his signature to give effect to the will; and
c) the signature is made or acknowledged by the testator in the presence of two or more witnesses present at the same time; and
d) each witness attests and signs the will in the presence of the testator, all present at the same time.
This would indicate that a will signed by an electronic signature may not be valid, due to the distinct nature of wills; case law has generally favoured a wet signature as this authenticates the document. There is some argument that electronic signatures might be acceptable, but case law is not definitive.
The Law Commission is currently reviewing this area of law and in particular the formalities for the signing of a valid will. Until this review is complete, it would be best practice to have all wills witnessed with wet signatures.