Welcome to Community, Felix02.
I'd be happy to share some information about adding logos to QuickBooks Online.
Adding two logos on the same form isn't available in QuickBooks Online. However, you can use a third-party application. You can visit the Intuit Marketplace to check for an app that can help to add multiple logos on an invoice.
I recognize the importance of having the option to add multiple logos in QuickBooks Online. This is why we make great efforts to deliver customer satisfaction at all times.
I encourage you to submit a request by going to the Gear icon in QuickBooks Online. Then, choose Feedback. From there, any suggestions are forwarded to the Product Development Team for consideration in future updates.
You can also read this article if you want to upload logos from your invoices, estimates, or sales receipts in QuickBooks Online: Add, customise, or remove logos on sales forms.
If there's anything else that I can help you with, please let me know in the comment section down below. I'll be always around ready to help.