is there a way to force a payment (receipt) for an invoice?

You can record invoice payments through Receive Payment, allas. 

Before anything else, could you clarify what you mean by forcing a payment on an invoice? Any details would be appreciated.

For the time being, if you want to record the payments received from an invoice, create a Receive Payment. This transaction marks the invoice as paid and reflects the payment in your accounts, ensuring accurate records. I'll show you how to do it:

1. Go to the + New button.
2. Select Receive payment.
3. Choose the customer from whom you received payment.
4. Select the invoice that you are receiving payment for and enter the amount paid.
5. Once done, click Save and close.

You'll also find that QBO allows you to send reminders to customers with outstanding invoices. This option enable you to remind customers about invoice due dates. Check out this article for more info: Send invoice reminders automatically or manually in QuickBooks Online. 

I'll include this article for your reference on personalizing your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.

On top of that, check out Intuit's QuickBooks Live Expert Assisted service, offering personalized video consultations with certified professionals. They deliver customized bookkeeping assistance and strategic insights.

As always, you can return to this thread with any follow-up questions about managing your invoices.