order router to an existing contract

I have recently bought the o2 homespot plan and missed to select the homespot router whereas I have received the sim card. I would like to order the router and attach it to the existing contract. Can I order it via website or is it only via customer service?

I saw a similar thread but didnt find links except the customer care number for which the waiting time is long. @o2_Giulia can you please guide me?

Edit o2_Larissa: moved from Homespot to English o2 Community: Mobile