Here are the key details about genmaicha:
The product page should be similar to the Barista premium grade product page.
The product is 100% organic.
It is made of 50% matcha and 50% rice.
50g packaging
Farmer or region unknown/not specified as it is a mix. 

Here’s some additional information to include on the page (copied exactly as provided):
"The matcha used is of high quality, therefore the result has a bright green color.
Regarding genmaicha powder, I was given a bit more information regarding the process of the genmai part:
Roasting method: Brown rice is usually roasted over high heat, but the one we use is roasted over medium heat to achieve a balance of aroma and taste.
Crushing method: A water-cooled crusher is used. By cooling the drum exterior and crushing zone with water or antifreeze, the temperature of the crushed material rises less, preventing deterioration due to heat.
For this genmaicha powder, we use high-quality matcha, which gives a better color and taste.
Also, and this is my guess, usually, for genmaicha powder, other companies who produce it use genmai (brown rice) and sencha, first to have a classic genmaicha, and then use a machine to make it a powder.
In your case, it is not sencha, it is a mix of matcha and genmai powder.
So the 2 elements are mixed together, while in other cases, whole genmai and sencha are mixed and then powdered."

Preparation:
Mix 1 to 2 g of genmaicha with 80 ml of hot water at around 70°C, depending on the desired intensity of flavor, then whisk until a light froth forms.
For a genmaicha latte, use 2 g of powder and mix 70% water with 30% milk (preferably oat milk). This blend perfectly highlights the delicate flavour of roasted rice.
Ingredients: Organic green tea & organic roasted brown rice
I'm also attaching the labels if I missed anything (or you can check them on figma).