You can pay your invoices from Comviq via Swish, both on comviq.se and the Comviq-app . Log in to My Account (Mitt Konto), go to Payment (betalningar) and then select the invoice you want to pay. Then you choose Swish as the payment method, enter the phone number (linked to your Swish) and complete the payment.
You can also use Swish as a payment method to top up your prepaid SIM card or mobile subscription.