Specifications of the front hub: 

Brand: BQ
Model: BQ-FH30503
Color: Black
Number of spoke holes: 36GTS
Type of brake: Disc (6 bolts)
Type of axle: Thru axle Ø 15 MM
Axle included: No
Type of bearings: Industrial bearings
Average weight (GR): 197
Intended use: E-Bike
 
Data for spoke length calculations using the Sapim spoke size calculator: 
Total length of the hub (MM): 110
Non-gear side (MM): 26
Gear side (MM): 14
Hub diameter non-gear side (MM): 58
Hub diameter gear side (MM): 58
 
Link to spoke calculator: www.sapim.be/spoke-calculator