The answer "For the front you will want a G2 Hypoid Oil, this is the Genuine fluid: https://www.fcpeuro.com/products/bmw-g2-hypoid-differential-fluid-500ml-genuine-bmw-83222413511". But on this page, 2019 BMW X5 x40i is not listed, and it says "Part may not fit". Can you please clarify? Thanks.
G2 Hypoid gear oil is used in almost all front BMW differentials, and this (83222413511) is the part number BMW provides for 2019 X5 x40i.
Here are some links you can use to see what I am referencing - G2 for the front of all F15 models -
https://www.realoem.com/bmw/enUS/partxref?q=83222413511&series=F15
And G3 for the rear -
https://www.realoem.com/bmw/enUS/partxref?q=83222413512&series=F15
If you have any other questions regarding fluid specs, compatibility, repair procedures, etc, you are always welcome to contact service@fcpeuro.com and we can provide more details.