Proof and translation of UK evisa

I am in the process of applying for Romanian nationality and they are asking for proof of my ILR in the UK (I am Canadian). The problem is that I have an evisa. How can I have this translated and apostille sealed to prove to a foreign government that I have ILR in the UK? Without physical documentation I am scratching my head a bit. Does anyone know if the Home Office would issue a confirmation letter or something of that sort? Thanks.