Adding a second string of solar panels - can I do it myself?

We are getting an extension with a flat roof on which we'd like to fit additional solar panels.
We currently have a 2.4kW array facing South East and the new panels will face South West.
The new array is will be about 2.5kW.
I see our current inverter (GIV-HY3.6) is capable of connecting to two strings of panels.
I would like to connect them myself, electrically it looks very straight forward but I am not sure if I legally am permitted to do so.
Also, will the inverter automatically detect the panels or will it need to be re-configured by a GivEnergy engineer?
Thanks in advance!

No problem. If only one set of the 'MC4' connectors is in use on the inverter, then connect the new panels to the unused pair and it'll just work. One of the bits of the 'closed ecosystem' that is happy with owner/user changer. 🙂

montybigglesworth with a flat roof on which we'd like to fit additional solar panels.

You are probably aware, but just in case... I beleive you need planning permission/building regs(?) if installing panels onto a flat roof

I am just considering doing the same thing - I have GIV-HY5.0 and all my current panels are on one string. I want to add 4 more panels facing west and my inverter supports 2 PV strings.
Did you DIY it? Or does it have to be provisioned by someone with access to the GE backend?
Thank you