hello,
I'm an agent.
When I would like to order as a customer. I can not

WHY?
hello,
I'm an agent.
When I would like to order as a customer. I can not

WHY?
Hello,
Are you also using B2BKing on this site? Can you please check payment methods are enabled in B2BKing -> Groups for the customer?
Other than that, it is hard to say what it could be.
Can you share a temporary backend access so we can check directly? And what agent / customer are you testing with?
Kind regards,
Stefan