Ancestry ILR: lost birth certificate!

[Kbh2019]

Hi there

I have been in the UK almost 5 years now and am reaching the end of my ancestry visa validity so am applying for ILR. I have just realised that my birth certificate is nowhere to be found (and I stupidly did not make any copies, digital or otherwise) and I have seen at the end of the application that it is a supporting document (but not under 'mandatory'). Applying for a new one from South Africa could take months, so I'm just wondering what my options are? Could my ILR be refused if I dont have this document (even though I used it to apply for and be granted the ancestry visa)? Would I need to extend my current ancestry visa to remain in the UK?

Any advice would be much appreciated!!