Solar Commissioning certificate for electricity supplier

[Lm5861]

Hello,
Signing up with my current electricity supplier for export after recent solar install.
They stated they require a commissioning certificate to complete my application for export.
I’m looking to know what form this certificate takes, what it contains etc so my electrician can sort me out with what I need.
I’ve already completed and had accepted my g98 submission to REC.
Thanks

 

[snowhead]

Feed in Tariffs: Guide to Commissioning

This guide will help you to establish the date that your installation commissioned when you apply for the Feed-in Tariffs (FIT) scheme.

www.ofgem.gov.uk

 

[SWDweller]

What Utility and what are their rules on Net Metering