Hi,
Not much parts info online.
You may have to [https://www.ilve.com.au/support/spare-parts/|contact] ILVE and ask them for the part number.
I found this one for an [https://m.bigwarehouse.com.au/ilve-microwave-oven-iv600bim-light-p-1892828.html?cPath=86916_87331_87333|ILve IV600BIM] which might be the same as the oven model numbers are very close. maybe ask ILVE to confirm.
Not sure if this is applicable to your model but here's the ifixit [guide|76079] guide that may help.
If you do have to replace it as per the guide then as you will be working in the back of the oven, ''***be safety aware*** when working in microwave ovens. The HV capacitor can store >5000V DC for months even if the power has been disconnected for this length of time. This amount of ***voltage can seriously injure you***. The HV capacitor needs to be correctly discharged as soon as it is accessible after the oven's cover has been removed and before commencing any further work in the oven.''