Hi,
As you know, we don't use Liqpay. Interkassa is linked to Liqpay, but they need your actual IP and phone to check that you are you and nobody else. Try to deposit via Liqpay using Russian page of the billing. Select "Deposit" under your balance amount:
(All suggested options are highlighted in blue)
Select Option 2 to deposit via Interkassa and add the amount required in the window (5USD by default)
In Interkassa page, you will not be able to see Liqpay among payment systems
You will need to scroll down the page and select
Other payment methods (see the pic), among which you will see Liqpay
Try and leave feedback on how it worked (or not worked) for you.