Transmission gearbox capacity

Yesterday I changed the transmission oil (not the carc). I had a new bottle of ENI 85W/90.
When refilling I had the bike on the side stand and filled it until it was about to come back out the side filler whole. It took the 1 liter bottle. I seem to remember that in the past I always had some left over. After I looked at the manual and it seems to say only use half the 1 liter bottle. That didn’t fill it up to the inspection / drain port. Can someone tell me what is proper? Do I need to have the bike more upright where it wouldn’t have filled as much?
Should I drain half back out? Thank you!

Massively overfilled. Bike should be upright and filled to the bottom of the filler hole. 0.5 litre is the factory recommended amount but it may be a bit more.

Pete
Many thanks for the quick reply. I did what the shop manual said and filled it up the the filler hole
level, but the bike wasn’t level (small detail). I’ll drain about half back out or just open the side port with the bike level and let it drain that way.