Add more SIM cards to my account

I have had an account for a few years which does my home wifi. I ordered two SIMS on Amazon, one for my phone, and another for a travelling wifi

I am finding it very difficult just to manage this all from one dashboard

The best I can find is "create another account, register them under a different email!", then create a group account and then add them to a group account. But when i try to create a group account its offereing me different mix and match price plans. 

I just want one dashboard to manage several SIM cards and pay separately for each? It must be possible. Many thanks