How do I handle payment issues when applying for a Thai visa online?

Hi all, I’m struggling with the Thai govt visa application on the payment part and sound advice would be greatly appreciated.

I’ve saved the document in its entirety & have tried to submit it. It’s not clear to me but is the application pending before payment or do you submit payment with the application? 🙃 the page appears “stuck”. Also I can’t find a reference number anywhere as per the page photo.